tps_cold rolled

HIGH CARBONALLOYSPECIALTYSPRING STEEL

COLD ROLLING

CONTINUOUS STRIPELECTRON BEAMWELDING

SLITTING AND EDGING

HARDENINGAND TEMPERING

THEISPRECISION STEELCORPORATION

THEIS Precision Steel Corporation

THEIS PRECISION STEELQUALITY POLICY

Working safely together to provide ourcustomers top quality steel, on-time

and at the lowest cost possible

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TABLE 20: Some useful conversion factorsTo convert from To metric Multiply by(English unit) (SI) (Factor)Inch (in) Millimeter (mm) 25.4Inch (in) Meter (m) 0.0254Feet (ft) Meter (m) 3.048Pound (lb) Kilogram (kg) 2.2046Ton (short; 2000 lb) Kilogram (kg) 907.18Ton (long; 2240 lb) Kilogram (kg) 1016.0lb/in2 (psi) N/mm2 (or 1 Mpa) 0.006896lb/in2 (psi) kg/mm2 1422.334lb/in2 (psi) Kilopascal 0.1450377U.S. quart Liter 1.057Microinch(µin) Micrometer (µm-micron) 0.0254fpm (ft/minute) meter/minute 3.281RA RMS 1.11thou (milli-in or 0.001") Micron (mil) 0.03937Fracture toughness-Ksi in Mpa m 1.098PIW (lbs. per inch of width) kg/mm 0.017857

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Your source for engineered steelWhen you select Theis Precision Steel, you getmore than just a base metal supplier. You gain apartner in the successful design and productionof your products. Through early and continuoussupplier involvement, Theis can help you designyour materials, parts and processes to work to-gether to cut costs and improve delivery sched-ules. It is our goal to help you produce better prod-ucts and provide better service to your custom-ers. Find out what Theis can do for you. Contactus for a free needs analysis.

Strip Steel Weight Calculations:Lbs per lineal foot = 3.4 x Thickness (in) x Width (in)Lbs per foot = W (in) x T (in) x 0.283 x 12Coil weight = lbs. per foot x coil widthPIW (lbs. per inch of width) = Coil weight/coil widthCoil length (feet) = Coil weight/lbs. per foot

THEISPRECISION STEELCORPORATION300 Broad Street, Bristol, Connecticut, U.S.A. 06010Tel: (860) 585-6610 FAX: (860) 589-7411e-mail: [email protected]

Sales: 860-585-6610Plant: 860-589-5511

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Engineered Steelsfrom Theis Precision SteelTheis Precision Steel is dedicated to the design andproduction of high quality engineered steel. Theconcept behind engineered steel is to design anddeliver a base material which improves the func-tion of your end product. By including characteris-tics of the finished part such as heat treating orsurface finishing in the base material, it may bepossible to reduce the number of manufacturingprocesses required to create a part. By participat-ing as a manufacturing partner in the design andproduction planning stage and using our experienceto match the characteristics of our steel exactly toyour application, we can help you deliver thehighest quality products faster and at a lower cost.

This brochure introduces the wide range ofTheis standard and custom engineered steels, andoffers guidelines for identifying and specifying thematerial tailored to your requirements.

Predesigned Engineered Steel: These productsare designed to provide superior performance inthe manufacture of certain standard parts. There arespecific grades of each material available whichcan be customized, and if one of these productsmeets your requirements, much of the engineeringis already done, bringing you closer to production.Custom Engineered Steel: Theis metallurgicalengineers analyze your requirements based uponthe cold rolled steel specifications you supply, andspecify the exact steel for your application. Toassist you, this specification process is carefullydescribed in this brochure, andshould you require further guidance,a knowledgeable Theis expert isalways available to answer yourquestions.

At Theis Precision Steel wepride ourselves on havingthe stock on hand for fastservice, the knowledge tomatch your technicalrequirements, and the facilities to produce thehighest quality product to your exact specifications.

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Table of ContentsRaw material cross reference ..................................... 2Specifying custom engineered steel ............................ 3Bartemp-B® (Bartemp) ............................................... 3Pinpoint carbide ........................................................ 3Hardened and tempered alloys .................................... 3Theis-ite® .................................................................. 3Bartex® ..................................................................... 4Electron beam welding (Barcomp®) ............................. 5 Saw Products........................................................... 6 Scoring Rule Applications ........................................ 6 Paper Industry Applications ...................................... 6 Electronic Applications ........................................... 7Testing and specifying mechanical properties .............. 7Equivalent hardness and tensile strengths .................... 9Formability ............................................................. 10Bend axis ................................................................ 11Bend Radius ............................................................ 12Annealed and hard rolled carbon steel Mechanical property ranges .................................... 12 Formability values ................................................. 12Hardness vs. vise break: high carbon steel strip .......... 13Microstructure ........................................................ 14Surface condition .................................................... 15Finish ..................................................................... 15Edge ....................................................................... 16Size tolerances ........................................................ 16Other tolerances...................................................... 18Flatness .................................................................. 18Camber ................................................................... 19Packaging ............................................................... 19Major specifying criteria ......................................... 19Typical applications of various TPS grades ................ 20Useful conversion factors ........................................ 21Strip steel weight calculations .................................. 21


TABLE 1: Cross Reference of Theis Precision Raw MaterialTHEIS PRECISION STEEL U.S.A. JAPAN GERMANY U.K. CANADA MEXICO FRAN. CHINA SWEDEN INT.

Steel UNS ANS!/ AIME/ AMS/ DIN (AISI) NAT'LTRM# Type Chemistry # ASTM AISI SAE Military Federal JIS Stoff-NR BS CSA NOM NFA GB, YB SIS ISO

14 PC C 0.50 G10500 A682 & 1050 5085D Mil-S- QQ- G4802 (CK 55) 149- 1050 B-203 XC 48- GB 3522- 141674- 4960Mn 0.75 A684 SAE- 16974 S-635 S50 1544- Part 1 1050 H 1 TS 50 1674 CS50

1050 1050 C-CSP 1.1203G 50 HS17222

15 PC C 0.28 G15270 1527 DIN 17200 B-301 YB-13 683High Mn 1.50 1.1170 1527 128Mn Mn6

26 PC C 0.65 G10640 A682 & 1064 1065 G4802 (CK 67) 970- 1064 B-301 XC60 GB 3522- 141665-Mn 0.67 A684 S65 C- 1544- Part 1 1064 60 1665

1065 CSP 1.1231 G 060A6717222

34 PC C 0.75 G10740 A682 & 1074M AMS Mil-S 700D- G4802- 1544 149- 1074 B-301 XC 75 141774- 4960Mn 0.60 A684 5120J 46049 1074 S70 C- 11.1248 G Part 1- 1074 M-71 1774 CS75

1074 SAE 1074 CSP 17222 HS 801074

37 PC C 0.80 G10860 A682 & 1086M AMS- QQ- G4802- (CK 85) 149- 1086M B-301 XC85 GB 1222- 4960Mn 0.42 A684 5112 S-700 G-4401 1544- Part 1 1086 85 CS85

SAE SK-5- 1.1269 G HS 80J1397 CSP 17222

54 PC C 0.97 G10950 A682 & 1095 AMS- Mil-S- QQ- G4802 (CK 101) 149- 1095 B-301 XC 100 141870- 4960Mn 0.40 A684 5121F 7947 S-700 SK4- 1544- Part 1 1095 1870 CS95

1095 SAE- C1095 CSP 1.1274 G HS 95J403 17222

61 Alloy C 0.33 SAECr- Mn 0.75, Cr 0.95 6135Mo- Mo 0.22, V 0.20V

64 PC C 0.128 T723 02 W1A SAE QQ-T- G4401 125W/ 1407 B-82 A35-590 4957Mn 0.25 W1C J437 580- SK2 1663 W2 Y2 140C TC140

W209 W272 Alloy C 0.50, Mn 0.80 H61500 A505/ 6150M AMS Mil-S- G4802- 117222- 735A50 6150 B-300 50 CV 4 GB 1222 142230-

Cr-V Cr 0.95, Mo 0.50 A506 6455G 8503 G4801 1.8159 6150 50CrVA 2230V 0.20 6150 SAE- SUP 10- 50CrV4

6150 CSP73 Alloy C 0.74, Mn 0.65 A505/ SAE 9262 55SiCr7 GB 1222

Cr-Si Si 1.40, Cr 0.40 A506 J1249 60Si2CrA9262

74 Alloy C 0.70, Mn 0.40,Cr-Ni- Ni 0.75, Cr 0.50

Mo Mo .11578 Alloy C 0.35, Mn 0.75,

Cr-Mo- Cr 3.05, Mo 0.70,V V 0.30

80 Alloy C 0.32, Mn 0.72,Cr-Ni- Ni 0.60, Cr 3.10,Mo-V Mo 2.10, V 0.35

81 D6 C 0.47, K24728 A578 AMSAlloy Mn 0.75, Ni 0.60, 6431

Cr-Ni- Cr 1.00, Mo 1.00,Mo-V V .11

84 D6 C 0.29, Mn 1.025Alloy Ni 1.00, Cr 2.00

Cr-Ni-Mo- Mo 1.50, V 0.25V-Nb-W Nb 6.25, W 1.50

92 PC C 0.60, G92600 A505/ G4801 5026 970- 9260 B-297 6OSiCr7 GB 1222 683-14High Mn 0.87, Cr 0.42 A506 SUP 7 55Si7 Part 2 9260 60Si2MnSi Si 2.00 9260 251A60

PC: Plain Carbon, Cr: Chromium, Mo: Molybdenum, V: Vanadium, Ni: Nickel, Si: Silicon, Nb: Niobium, W: TungstonM: Modified

2

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SpecifyingCustom Engineered SteelProduct and end use requirementsThe initial step in developing a definitive specifica-tion is to review the part and application character-istics: How will the part be formed? How manybends and what angles are involved? What envi-ronmental conditions (temperatures, stresses, etc.)will prevail during its use? If material is beingreordered for an on-going manufacturing pro-gram, the production procedures should be re-viewed, to disclose any possible need for change inthe steel specification. Once manufacturing andend use considerations have been analyzed, thestage is set for writing the specification. For moreinformation on proper specifying criteria, seepage 19 of this brochure.

SIZE RANGES OF BAINITE:TRM-14: 0.015-0.080" (.38-2.0 mm)TRM-34: 0.015-0.080" (.38-2.0 mm)TRM-26: 0.025-0.080" (.64-2.0 mm)TRM-54: 0.025-0.080" (.64-2.0 mm)Other sizes available upon request. TRM = Theis Raw Material

BARTEMP-B® (BAINITE)Furnished in pre-hardened condition, this materialis tougher than BARTEMP-M (MARTENSITE),allowing the fabrication of parts where variousshaping technologies, such as blanking, bending,drawing, stretching, extrusion, coining, or swagingmight be involved. Because the material is alreadyhardened, the following benefits can be realized:

a) Additional steps to correct distortion inherentin part hardening are eliminated.

b) Closer dimensional tolerances and improvedfinish.

c) Parts require no further heat treatment, savingon labor, utility costs and capital equipment.

d) Lead times can be shortened.This material is available in the following grades:

TRM-14 (AISI-1050), TRM-26 (AISI-1065),TRM-34 (AISI-1074), TRM-54 (AISI-1095).TRM = Theis Raw Material

BARTEMP-B, made out of TRM-14 and TRM-26, canundergo considerable shaping. However, BARTEMP-B,made out of TRM-34 and TRM-54, is suitable for lightlyshaped components. For applications where good wearresistance is needed mostly along the edges of the material,it is recommended that higher grade BARTEMP-B be used.

TABLE 2: BARTEMP-BAISI TRM Thick- RC U.T.S. % Min. Bend Radius

# ness KSI Elong I Rolling Direction =in (mm) in (mm) in. (mm)

1050 14 .020 (.51) 44 210 7 .040 (1.02) .080 (2.03)1065 26 .028 (.71) 43 200 6 .060 (1.52) .095 (2.41)1074 34 .040 (1.02) 41 190 6 .080 (2.03) .100 (2.54)

.040 (1.02) 48 225 5.5 .125 (3.17) .170 (4.32)1095 54 .042 (1.07) 41 195 8.5 .090 (2.20) .110 (2.79)

PINPOINT CARBIDEThis structure is pre-heat treated and cold rolled. It isused extensively for band saw and other cutting appli-cations. Pinpoint carbide can have teeth punched,milled or ground easily at high hardness levels. Pulsehardening of the tips greatly enhances cutting proper-ties. It responds well to heat treatment, offering excel-lent fatigue and wear properties.

Pinpoint Carbide is available in the followinggrades:TRM-37 (AISI-1086M), TRM-54 (AISI-1095),TRM-64 (BARCOID®).

SIZE RANGES OF PINPOINT CARBIDE:TRM-37: 0.008-0.050" (.20-1.27 mm)TRM-64: 0.025"-0.050" (.64-1.27 mm)TRM-54: 0.010"-0.050" (.25-1.27 mm)

* Other grades and sizes by applicationTRM = Theis Raw Material

HARDENED & TEMPERED ALLOYSTheis offers hardened and tempered alloy steelfor many applications. The grades shown on page4 are selected as typical of our alloy steel offerings.

THEIS-ITE®

THEIS-ITE offers a combination of excellent form-ability and high strength. This allows for parts to beintricately shaped without expensive final harden-ing with its distortion and sorting problems. THEIS-ITE is supplied pre-tempered in thicknesses from0.004" through 0.065" (0.10-1.65 mm) and widthsfrom 0.25" through 12.5" (6.35-317.50 mm). Theis

TABLE 3: Pin Point CarbideAISI TRM# Thickness: in (mm) Hardness

1086 37 .014 (.36) 15N 78 - 83.025 (.64) 15N 76 - 79

1095 54 .010-.025 (.25-.64) 15N 76 - 83.025 (.64) 15N 74 - 80

Barcoid® 64 .032 (.81) 30N 48 - 58.035 (.89) 30N 48 - 57

3


4

TABLE 4: Hardened and Tempered AlloysGrade Thick- Hard- Ten- 0.2% % Vise Proper-

AISI TRM ness ness sile Y.S.Elong Break x ties# in (mm) RC KSI KSI Thick

High9260 92 .055 RC 43 200 175 7.0 wearmod. (1.40) resist.

HighD6A 81 .042 (1.07) 86 15N 215 200 5.0 17-20 fatigue

.010 (.25) 275 245 4.0 20-23 appln6150 72 .020 30N 73 298 240 5.0 20-22 Saw

(.51) partsHot metal

Barco 73 .022 30N 65 215 191 6.0 13-15 cuttingSil® (.56) appln

HighTheis- 15 .031 (.30) 80 15N 204 171 5.0 Forma-

ite® .015 (.38) 18.7 162 5.0 bility

TABLE 5: TheisiteTest With Max. Strength With Max. Ductility

Parameters .015" .020" .030" .042" .015" .042"in. (mm) (.38) (.51) (.76) (1.07) (.38) (1.07)Tensile* 187 220 204 185 130 160

0.1% Y.S.* 156 134 163 910.2% Y.S.* 163 152 171 105% Elong. 5.0 5.5 5.0 8.0 10.0

Modulus X106 29.6 29.7 30.0Hardness:

15N 82.5 7330N 60 64.0RC 40.5# 44.0# 42.0 42.0 28# 35

Vice Break 0.200Min. B.R**

Long. 1.7xT 3.5xT 2.0xT Flat onitself

Trans. 1.0xT 2.5xT 2.0xT 1.5xT Flat on 0.040itself 1.0xT

45 Deg 1.2xT 3.0xT 1.7xT Flat onitself

* = KSI, # = Converted, T = Thickness, ** = Bend Radius

will custom make THEIS-ITE to suit your require-ments. The accompanying table shows some typi-cal data of THEIS-ITE at various thicknesses.

TABLE 6: Thickness and width tolerancesSize + Tolerance for Max. VariationVariation indicated within a singleLimit: thickness coil

.004" to .009" 0.0003" 0.0003"(.10 to .23 mm) (.0076 mm) (.0076 mm)

Thickness .009" to .025" 0.0004" 0.0004"(.23 to .64 mm) (.01 mm) (.01 mm)

Width Tolerances for all coils within a lot:+0.0040" (.10 mm)

BARTEX®

BARTEX is a specially heat treated, cold rolledhigh carbon steel. In its delivered condition, Bartexhas a significantly higher tensile strength and yieldto tensile ratio compared to hardened and tem-pered material of similar dimensions. The mechani-cal properties of Bartex are further enhanced byusing a controlled strain aging heat treatment.

Based on specific applications, strain aging processcan be applied to the formed spring (as with constantforce springs) or the material prior to fabrication ofsprings (as with power springs).

Bartex uses selected raw material with a lowinclusion level, smooth and tight surface finish, andtextured grain orientation resulting from heavy coldreduction and close control of metallurgical proper-ties. This results in considerably improved fatigueproperties, provided that good practices are used tocontrol stress raisers.

Although plain carbon steels having a carbonrange of 0.60% through 1.25% can be considered tomake a textured material, the most suitable grade isan eutectoid plain carbon steel (carbon 80%) whichis cold rolled to produce a 100% textured condition,and this is known as Bartex.

The following is some typical Bartex data:Dimensions:

Available thickness: 0.004 - 0.025" (.10-.64 mm)Available width: 0.093 -12.0" (2.36-304.8 mm)

Size: 16" (406 mm) I.D. unless otherwise specified.Maximum O.D. 48" (1219 mm) unless otherwisespecified.Surface Finish: Bright cold rolled, uncoatedcondition.Surface Coating: Parts made out of Bartex can becoated with metal or polymer provided the processtemperature does not exceed 480°F (249°C).Mechanical Properties: The properties vary ac-cording to the rolling direction. Material transverseto rolling direction has the maximum ductility. Thematerial is somewhat limited for forming.

Customers must do a low temperature strain ageat @464oF (240oC) for 1/2 hour for optimumspring properties.

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Typical Material Hardness (as delivered)HardnessH.S.S. Edging: HV 350 max (15N 78 max)E.B. Weld: HV 420 max (15N 82 max)Backing material (D6A): HV 250 max(15N 70 max)MicrostructureEdging: Fully spheroidized with primary carbidesizes of 1 to 3, with some large alloy carbides.Free from carbide segregation and total decar-burization (free ferrite). Partial decarburization

of 0.00040" (0.011 mm) maximum per side isallowed. No carburization is allowed.E.B. Weld: Typical annealed cast microstructure.Small uniform carbides of sizes 1 to 2 in an alloyferrite matrix.Backing: Spheroidized with occasional areas offine lamellar pearlite. Partial decarburization of0.0005" (0.013 mm) maximum per side allowed.No total decarburization (free ferrite) is allowed.

Weld SeamNo misalignment of edge and backing, overfillor undercut of the weld, and no excessiveporosity, blowholes or cracks.

SurfaceTypical lightly cold rolled dull surface, free fromexcessive scratches or roll marks. Material islightly coated with rust preventative oil. We canalso provide material with ground surface.

EdgesThe backing edge shall be a square edge withchamfered corners (corner radius) of.002 - .010" (.05 - .25 mm) or blunt round.The H.S.S. edge shall be #1 sharp square withmaximum chamfer of .003" (.076 mm)

Theis uses electron beam welding technologyextensively for welding high speed tool steel tohigh strength low alloy backing steel for the sawindustry. The same technology is used in fabrica-tions in these industries:Electronics:Stainless steel and various nickel alloys.Paper manufacturing:Monel to low alloy steel for doctor blade applications.Textile Industries:Hardened high carbon steels of dissimilar thicknesses.Scoring rules:Carbon steels of dissimilar shapes, which are difficultto fabricate using conventional shaping technology.

5

The following typical mechanical propertiesare obtained after a 464oF (240oC) stress relief:

Thickness Range: Less than 0.006" (0.15mm)

Tensile: 340-380 KSI (2346-2621 N/mm2)Vise Break: < 23 x Thickness% Elongation: < 1.0

Thickness Range: 0.0098M - 0.006" (.25 - .15 mm)Tensile: 320-355 KSI (2205-2448 N/mm2)Modulus: 29-30 Million PSI0.2%/UTS Ratio: 95-98 %0.010% Proof Stress: 310 KSI (2138 N/mm2)%Elongation: < 1.0Vise Break: Less than 22 x Thickness15N Hardness: 15N 86 - 88

Thickness Range: 0.025" -.010" (.64-.25 mm)Tensile: 270-330 KSI (1862-2276 N/mm2)%Elongation: 3 - 1Vise Break: 14 - 20 x Thick

ELECTRON BEAM WELDING (BARCOMP®)

Ductility: Good - FairConsult Theis Precision Steel for your specificapplication.Other Grades of Textured Material:Textured Materials using other carbon grades,such as TRM-26 (AISI 1065), TRM-34 (AISI1074M), TRM-54 (AISI 1095), etc. are producedby Theis. Each textured material has its own uniqueproperties and typical product applications. Sometypical data is as follows:TABLE 7: Bartex- Other Grades

Grade Thickness Tensile Vise BreakTRM# in (mm) KSI x thick

.005 (.12) 298 1326 .006 (.15) 287 12

.0076 (.19) 280 10.534 .0075 (.19) 305 14

.0094 (.24) 288 13

.0045 (.114) 280 1654 .0051 (.129) 270 15

.022 (.558) 255 14


Sizes and TolerancesMany sizes are available. The following typicalsizes available with respect to saw types:

Typical tolerances:Width: +0.002" (+0.051 mm)Thickness: +0.0010" (+0.025 mm)Camber: <0.180" in 6'

(<4.6 mm in 1.83 m)Flatness: <0.001"/1" of width

(<0.025 mm/25.4 mm width)Wedge/crown <0.001"/1" of width

(<0.025 mm/25.4 mm width)Dog legs (TIR) <0.020" in 20.0"

(<0.50 mm in 508 mm)

CoilsTheis will meet customer specifications for coilI.D., O.D., length, matched coils, color code,butt weld and packaging.Scoring Rule Applications:Cold drawn high carbon shaped wire in typical sizes of0.084" x 0.150" (2.13 x 3.81 mm) and 0.112" x 0.150"(2.84 x 3.81 mm) are electron beam welded to a sec-tion of 0.042" x 1.10" (1.07 x 27.94 mm) of similargrade. This creates a shape difficult to make using con-ventional rolling and/or wire drawing methods. It isalso possible to weld dissimilar steels.

Paper Industry Applications:Solid high strength Monel (copper-nickel alloy) isan expensive material used to make doctor blades.When it is reduced by usage to a predeterminedwidth, the blade must be discarded. To reducecosts, thin strips can be welded to less expensivelow alloy steel. Typical size configuration of a0.035" (0.89 mm) thick trimetal application:

Monel Low Alloy Steel Monel

6

TABLE 9:Saw Types wih Thickness/Width Tolerances

Saw type Thickness Width Edge widthinch (mm) inch (mm) inch (mm)

Hand hack 0.024 (0.61) 0.500 (12.7) 0.040 (1.02)Power hack 0.050 (1.30) 1.125 (28.6) 0.156 (4.00)

& 0.186 (4.73)0.088 (2.23) 1.075 (27.3) 0.250 (6.35)

Hole 0.050 (1.27) 1.500 (38.1) 0.187 (4.75)Band 0.025 (0.63) 0.250 (6.35) 0.040 (1.02)

0.042 (1.07) 1.250 (31.75) 0.060 (1.52)Reciprocating 0.035 (0.89) 0.750 (19.0) 0.040 (1.02)Saber 0.050 (1.27) 0.750 (19.0) 0.060 (1.52)Porta band 0.020 (0.51) 0.500 (12.7) 0.040 (1.02)

TABLE 8: Typical chemical composition of backing and edging materialM2 M3T1 M42 MATRIX II D6A 3% CR- AISI 6150 AISI 6135 TRM 84

Element HSS edge HSS edge HSS edge HSS edge backing backing backing backing backing

C .79-.86 1.00-1.10 1.05-1.10 0.70-0.75 0.45-0.50 0.30-0.35 0.48-0.53 0.30-0.37 0.26-0.32Mn <0.35 0.20-0.35 0.15-0.30 0.15-0.40 0.60-0.90 0.65-0.80 0.70-0.90 0.60-0.90 0.95-1.10Cr 3.90-4.40 3.75-4.50 3.50-4.00 3.90-4.40 0.90-1.10 3.00-3.20 0.80-1.10 0.80-1.10 1.90-2.10Mo 4.75-5.25 6.00-6.50 9.25-9.75 4.75-5.25 0.90-1.10 2.00-2.20 0.40-0.60 0.15-0.36 1.40-1.60V 1.75-2.05 2.40-2.80 1.00-1.30 0.80-1.10 0.08-0.15 0.30-0.40 0.15-0.25 0.15-0.25 0.20-0.80W 6.00-6.75 6.00-6.50 1.30-1.70 0.80-1.10 1.40-1.60Co 7.75-8.25 7.75-8.25Ni 0.50-0.70 0.30-0.90Cu <0.20 0.20Al 0.05-0.10 0.05-0.10 0.03-0.10 0.05-0.10 0.05-0.10 0.40-0.80 0.04-0.10 0.04-0.10 0.04-0.80Si 0.15-0.35 0.20-0.35 0.20-0.35 0.15-0.30 0.10-0.25 0.30-0.45 0.20-0.35 0.15-0.30 0.30-0.50S <0.015 <0.01 <0.010 <0.010 <0.007 <0.010 <0.010 <0.010 <0.004P <0.025 <0.025 <0.025 <0.025 <0.015 <0.015 <0.025 <0.025 <0.020

NOTE: Theis will be pleased to work with customers in developing new grades of HSS edging and backing material

Saw Products

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of the application requirements. As a guide fortesting and specifying, it should be noted that therelationship between tensile strength and hard-ness is similar for all high carbon steels.

Hardness or tensile strength should be speci-fied as a range of minimum-maximum values toavoid costly overspecification. This range can bebased on tests of hardness or tensile strength orcan be deduced from desired performance char-acteristics.

When performance characteristics are used todetermine hardness, design stresses, tensilestrength or temper they should be explicitly notedso that the supplier and user can double-check thespecification.

By analyzing design stresses in a strip steelapplication, design engineers can estimate therequired yield strength and then calculate theultimate tensile strength for the material. For mosthardened and tempered high carbon strip, mini-mum yield strength is approximately 85% of theultimate tensile strength.

Whether hardness specifications are based oncalculated mechanical properties or on test re-sults, an understanding of common hardness testscan help designers, engineers and purchasersspecify hardness accurately.

Specification Based on TestsStrip steel specifications should be based on

tests whenever samples are available. Rockwellhardness tests are the most widely used in the U.S.for several reasons, including speed and the rela-tively low cost of the equipment. In a Rockwell test,the material is simply placed on an anvil andsubjected to the pressure of either a diamond coneor a ball penetrator, first under the weight of arelatively light, or “minor” load, and then subse-quently under the greater weight of a “major”load. Exact load weights involved determine thespecific scale. Test values directly indicate thedifference in depth of penetration under theweight of the minor and major loads.

Two types of Rockwell testers are used fordifferent strip thickness ranges, and each type,using a diamond cone penetrator, provides mea-surements in three hardness scales, which aredifferentiated by the mass of the major load. (Thediamond cone penetrator scales are used when-ever hardened and tempered steel or other hardmaterials are to be tested.)

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Testing and SpecifyingMechanical PropertiesHardness and Tensile Strength

The most common mechanical properties speci-fied are hardness and/or tensile strength. Theseare controlled by annealing, cold working or hard-ening and tempering, and always specified in light

FIGURE 1:Enlargements of weld cross sections

Electronic Applications:Iron-nickel alloy is typically welded to AISI 304type of stainless steel as tri-metal in various sizes.This welding requires a high degree of skill andprecision.

Typical size configuration of a trimetal application:

S.S. Invar S.S.

37 XStandard band saw

18 X 50 X

8 X 18 X

Dissimilar Shapes

Dissimilar Thicknesses


The standard tester is armed with relativelymassive major loads of 150 kg, 100kg, and 60kg forthe Rockwell C, D, and A scales, respectively; theminor load in all three cases is 10kg. The superfi-cial tester makes use of major loads of 45 kg, 30 kg,and 15 kg for the Rockwell 45N, 30N, and 15Nscales, respectively; the minor load for each ofthose three scales is 3kg.

The Diamond Pyramid Hardness (DPH) testuses even lighter loads - 2 kg, 1 kg, and 1/2 kg - tomeasure the hardness of the very thinnest gaugesof strip steel. Each test involves only one load;there is no minor load. Diagonal dimensions,rather than the depth of the indentation aremeasured, and a single scale is used for allpenetrator loads.

To guarantee accuracy, sensitivity, and repeat-ability of the measured values, it is essential toselect the test and scale appropriate to the thick-ness of the strip to be tested. Refer to Table 10 forhardness scale vs. thickness of strip requirements.

Normally, a hardness test should be carriedout with the largest recommended load allowedon the penetrator to minimize the test’s sensitivityto surface variations and imperfections, such asmachining marks and decarburization. Scales basedon lighter loads should be avoided.

If, however, the strip is too thin to support thepenetrator load, the impression of the penetratorinto the strip will result in a bump or bulge on theunderside of the strip. The formation of such abulge is known as the “anvil effect” and usuallyindicates an inaccurate hardness reading.

Furthermore, with extremely thin strip, thereis the danger that the penetrator might actuallypierce the strip and dent the anvil itself, giving animproper reading and impairing the accuracy ofthe tester in future use.

Stacking several strips of the same material isnot recommended. The cushion-like spring actionbetween the strips will prevent an accurate reading.

Tensile strength testsTensile strength testing involves pulling a

sample in tension until it breaks. It is more time-con-suming than hardness testing, but has the importantadvantage of always using the same unit of measure-ment (psi), regardless of strip thickness.

Because tensile strength and hardness arerelated, the specifier can cite just tensile strength,or convert to a hardness value by using appropri-

ate conversion charts included in this brochure.

Conversion to other hardness scales ontensile values according to ASTM E-18There is no general method for accurately convert-ing the Rockwell hardness numbers on one scaleto hardness numbers on another Rockwell Scale,or to other types of hardness numbers, or totensile strength values. Such conversions are, at best,approximations and therefore should be avoided, exceptfor special cases where a reliable basis for the approxi-mate conversion has been obtained by comparison tests.

Specifying CautionsMany steel buyers have learned through experiencewhat specific Rockwell C-scale values are associatedwith their own applications. Other scales, such asRockwell 15N or 30N, are less well understood, andthus not as readily associated with product applica-tions. As a result, specifiers may cite a Rockwell C-scale hardness, regardless of the strip thickness, inorder to obtain a certain temper quality.

For example, a user may specify Rc48 hard-ness, even though the requested strip is only 0.020inches (0.508 mm) thick, just to indicate that thestrip should be given a full temper. This practicecan cause misunderstandings if the specifier failsto explain that it is not the tested C-scale hardnessitself that is desired, but the performance associ-ated with it.

Even more misleading is improper use ofhardness conversion charts. A person withoutexpert knowledge of the lighter hardness scalesshould never convert a C-scale value to a lighterscale for an equivalent temper. Even when a se-lected chart lists values that convert accurately interms of hardness, the converted values may notyield equivalent strip characteristics. To provideequal temper and spring characteristics in differ-ent thicknesses of a given steel, hardness andtensile strength must be increased when stripthickness is decreased.

A Rc48 hardness, for example, will be a fulltemper in strip more than 0.035 in. (0.89 mm)thick, but the equivalent hardness (by conversion)of R30N 66.5 will be less than a full temper in stripthat is 0.025 in. (0.63 mm) thick.

Those who wish to specify a Rockwell 15N or30N hardness offering spring characteristics equiva-lent to those of a known C-scale hardness can usethe comparison charts shown in Table 10.

8

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TABLE 10: Approximate equivalent hardness numbers and tensile strengths

DPH TENSILE TENSILEROCKWELL (VICKERS) STRENGTH STRENGTH

HRC HRA 30 N 15 N HRB 30 T 15 T150 kgf 60 kgf 30 kgf 15 kgf 60 kgf 30 kgf 15 kgf 10 kgf N/mm2 KPSIBrale Brale Brale Brale 1/16"Brale 1/16"Brale 1/16"Brale68.0 85.6 84.4 93.2 94067.5 85.3 84.0 93.0 92067.0 85.0 83.6 92.9 90066.4 84.7 83.1 92.7 88065.9 84.4 82.7 92.5 86065.3 84.1 82.2 92.3 84064.7 83.8 81.7 92.1 82064.0 83.4 81.1 91.8 80063.3 83.0 80.4 91.5 78062.5 82.6 79.7 91.2 76061.8 82.2 79.1 91.0 74061.0 81.8 78.4 90.7 72060.1 81.3 77.6 90.3 70059.7 81.1 77.2 90.1 69059.2 80.8 76.8 89.8 680 2448 35558.8 80.6 76.4 89.7 670 2400 34858.3 80.3 75.9 89.5 660 2358 34257.8 80.0 75.5 89.2 650 2317 33657.3 79.8 75.1 89.0 640 2262 32856.8 79.5 74.6 88.8 630 2227 32356.3 79.2 74.2 88.5 620 2207 32055.7 78.9 73.7 88.2 610 2138 31055.2 78.6 73.2 88.0 600 2089 30354.7 78.4 72.7 87.8 590 2055 29854.1 78.0 72.1 87.5 580 2020 29353.6 77.8 71.7 87.2 570 1986 28853.0 77.4 71.2 86.9 560 1952 28352.3 77.0 70.5 86.6 550 1903 27651.7 76.7 70.0 86.3 540 1862 27051.1 76.4 69.5 86.0 530 1827 26550.5 76.1 69.0 85.7 520 1793 26049.8 75.7 68.3 85.4 510 1752 25449.1 75.3 67.7 85.0 500 1703 24748.4 74.9 67.1 84.7 490 1662 24147.7 74.5 66.4 84.3 480 1620 23546.9 74.1 65.7 83.9 470 1572 22846.1 73.6 64.9 83.6 460 1538 22345.3 73.3 64.3 83.2 450 1496 21744.5 72.8 63.5 82.8 440 1462 21243.6 72.3 62.7 82.3 430 1414 20542.7 71.8 61.9 81.8 420 1372 19941.8 71.4 61.1 81.4 410 1331 19340.8 70.8 60.2 80.8 400 1289 18739.8 70.3 59.3 80.3 390 1255 18238.8 69.8 58.4 79.8 380 1220 17737.7 69.2 57.4 79.2 370 1186 17236.6 68.7 56.4 78.6 360 1152 16735.5 68.1 55.4 78.0 350 1096 15934.4 67.6 54.4 77.4 340 1069 15533.3 67.0 53.6 76.8 330 1034 15032.2 66.4 52.3 76.2 (107) 320 1007 14631.0 65.8 51.3 75.6 (107) 310 979 142

9

Hardness Scale vs. Thickness of Strip Requirements:RC: > 0.035" (0.89 mm) RA: > 0.025" (0.64 mm) 30 N: > 0.020" (0.51 mm) - < 0.035" (0.89 mm) 15N: > 0.012" (0.30 mm) - < 0.020" (0.51 mm)HB: > 0.030" (0.76 mm) 30T: > 0.015" (0.38 mm) - < 0.030" (0.76 mm) 15T: > 0.010" (0.25 mm) - < 0.020" (0.51mm) DPH: <0.012" (0.30 mm)


TABLE 10 (continued): Approximate equivalent hardness numbers and tensile strengths

DPH TENSILE TENSILEROCKWELL (VICKERS) STRENGTH STRENGTH

HRC HRA 30 N 15 N HRB 30 T 15 T150 kgf 60 kgf 30 kgf 15 kgf 60 kgf 30 kgf 15 kgf 10 kgf N/mm2 KPSIBrale Brale Brale Brale 1/16"Brale 1/16"Brale 1/16"Brale

Hardness Scale vs. Thickness of Strip Requirements:RC: > 0.030" (0.76 mm) RA: > 0.030" (0.76 mm) 30 N: > 0.020" (0.51 mm) - < 0.030" (0.76 mm) 15N: 0.008" (0.20 mm) - < 0.020" (0.51 mm)HB: > 0.030" (0.76 mm) 30T: > 0.020" (0.51 mm) - < 0.030 (0.76 mm) 15T: 0.008" (0.20 mm) - < 0.020" (0.51 mm) DPH: < 0.008" (0.20 mm)

29.8 65.2 50.2 74.9 (105.5) 300 952 13829.2 64.8 49.7 74.6 (104.5) 295 938 13628.5 64.5 49.0 74.2 (104) 290 917 13327.8 64.2 48.4 73.8 285 897 13127.1 63.8 47.8 73.4 (103) 280 889 12926.4 63.5 47.2 73.0 (102.5) 275 876 12725.6 63.1 46.4 72.6 (102) 270 862 12424.8 62.7 45.7 72.1 265 841 12224.0 62.4 45.0 71.6 (101) 260 827 12023.0 62.0 44.2 71.1 100 255 807 11722.5 61.5 43.4 70.6 250 800 11621.3 61.2 42.5 70.1 98.5 82.0 93.0 248 781 11420.3 60.7 41.7 69.6 98.0 81.8 92.5 240 758 110

(18.0) 59.0 97.0 81.1 92.1 230 717 104(17.0) 58.9 96.0 80.4 91.8 222 703 102(15.7) 58.3 95.0 79.8 91.5 218 689 100(14.3) 57.6 94.0 79.1 91.2 213 676 98(13.0) 57.0 93.0 78.4 90.8 207 662 96(11.7) 56.4 92.0 77.8 90.5 204 648 94(10.2) 55.8 91.0 77.1 90.2 196 620 90(9.2) 55.2 90.0 76.4 89.9 188 600 87(8.0) 54.6 89.0 75.8 89.5 184 593 86(6.9) 54.0 88.0 75.1 89.2 180 579 84(5.8) 53.4 87.0 74.4 88.9 177 565 82(4.7) 52.8 86.0 73.8 88.6 173 552 80(3.6) 52.3 85.0 73.1 88.2 169 545 79

FIGURE 2:Formability sketch

FORMABILITYFormability - the capacity of steel to sustain trans-verse or longitudinal bends without failure - de-pends on strip ductility. This is developed throughproper specification of analysis, hardness andmicrostructure. Also, formability is greatly influ-enced by the manufacturing conditions: fabricat-ing method (e.g., stamping, piercing, coining),orientation of bending axis to direction of grain,and the bending radius relative to stock thicknessand hardness. It is important to specify andunderstand all factors affecting formability.Formability of untempered strip is determined bya bend test. A sample is slowly bent over 180° untilits ends are parallel. The measured distance be-tween ends (Nt) is the multiple of strip thickness(t) that should be specified, for transverse ( l ) andlongitudinal (=) bends.

10

Longitudinal Bend

N1 t

Indicates direction of rolling

N1

Traverse Bend

t

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FIGURE 4: Effect of hardness and bend axis torolling angle on formability of AISI 1050 strip

Table 11 lists mechanical properties for vari-ous thicknesses and grades of as-rolled, annealedand BarcoForm® steel; Table 12 adds formabilityvalues for the same annealed and Barco-Formgrades. (Barco-Form is a spheroidized annealedproduct of Theis Precision Steel.) Obviously, thelow-hardness, annealed materials have the highestductility and will accept the most severe bends.

Table 12 indicates that Nt/t is 2, parallel to thegrain (=), when t=0.040" (1.016 mm). Therefore,the measured distance between parallel ends Nt=2X 0.040" (1.016 mm), or 0.080" (2.032 mm).

Formability of pretempered stripBoth bend and break tests are used to measure theformability of pretempered steel, with the choiceusually based on relative strip hardness.

Another means of judging the formability ofpretempered material is the vise break test, inwhich a sample strip is bent into a “U” shape in thejaws of a vise until it breaks. The vise breakdistance - space between jaws at fracture - isspecified in terms of a “go” and “no-go” rangewhich defines the required ductility. A large breakdistance indicates low ductility; a small distancerepresents a steel with better ductility but lowerresistance to service stresses. (The specified visebreak range must be compatible with the speci-fied hardness range.)

Table 13 shows formability values for 0.70 to1.05% carbon strip, plotting the break ratio V/t(vise break distance divided by strip thickness)against hardness.

FIGURE 3:Blanking and bending angles in relation to grain flow in steel strip

11

Formability Test - Untempered Strip

Bend Axis:Special consideration may be needed in the

formability section of a specification, in light ofthe ultimate part configuration and bends re-quired to achieve that shape. Ideally, the axis ofeach bend should be oriented transverse (90°) tothe direction of rolling direction. In practice, com-promises to this rule are often necessary. For ex-ample, the bend axis may be altered from the idealfor blanking economy, to minimize scrap. If thepart will receive several bends at various angles,it must be oriented for the best overall result.

Figure 3 illustrates how selection of the blankingangle will affect bend axis, and can be ma-nipulated to yield the most desirable bendingangle. It is recommended that critical bends be ori-ented a minimum of 30° to grain direction; more ifpossible.

Figure 4 shows formability of AISI 1050 strip ofvarying hardness, and different degrees of bendaxis orientation to rolling direction.

Fractures occurabove curve

Radius of bend=1 X thickness of stock

(1Nt)

42

40

38

36

34

32

Hard

ness

, Rc

0o 15o 30o 45o 60o 75o 90o

0o

90o

60o

30o

45o30o0o

Blanking Angle

60o45o90o

> > > > Rolling Direction > > > >

Bending Angle


TABLE 12: Formability values for annealed gradesThickness, t Direction Nt/t Nt/t Nt/tinches (mm) of bend Ann BarcoForm Ann BarcoForm Ann BarcoForm

.076" (1.93 mm) _I_ 2 0 2 0 2 0and over = 4 3 4 3 4 5

0.036-0.075" _I_ 1 0 1 0 2 0(.914-1.905 mm) = 2 1 2 1 3 2

0.015-0.036" _I_ 0 0 1 0 1 0(0.381-0.914 mm) = 1 0 1.5 1 2 1

0.008-0.014" _I_ 0 0 1 0 1 0(0.2037-0.356 mm) = 0 0 1 0 1 .5

TABLE 11: Mechanical property ranges of annealed and hard rolled carbon steelTRM and range of carbon and manganese contentTRM-14 TRM-31 TRM-34 TRM-54C .47-.56 C .65-.75 C. 68-.80 C .90-1.05

Strip HDNS Mn .60-.90 Mn .35-.50 Mn .50-.80 Mn .30-.50Thickness or UTS As hard Barco As hard Barco As hard Barco As hard Barco

rolled Ann.* Form rolled Ann.* Form rolled Ann.* Form rolled Ann.* Form

.076 " RC 14-29 16-30 16-30 16-32(1.93 mm) RB 95-106 85 80 97-107 87 85 97-107 89 87 95-107 92 90

and UTS (KSI) 95-135 85 80 105-150 87 84 105-150 88 85 105-160 95 92over % EL-2" min 20 28 15 20 15 20 15 20

.036" RC 14-27 15-29 15-29 15-30(0.914 mm) RB 95-105 85 80 95-105 87 83 97-105 89 86 97-107 92 88

and UTS (KSI) 97-130 85 80 105-145 87 83 105-145 87 85 97-155 95 90over % EL-2" min 20 28 15 20 15 20 15 20

.015" 30T 74-84 73 70 78-84 74 72 78-84 75 73 78-85 77 74(0.381 mm) UTS (KSI) 95-130 85 80 90-118 85 83 92-118 85 83 97-150 92 85

TO .035" % EL-2" min 20 28 20 25 20 25 15 20(.889 mm)

.008" 15T 90-93 87 86 90-93 87 86 90-93 88 87 90-94 91 89(0.203 mm) 15N 90-125 78 89-118 80 89-118 83 89-125 90

to .014" UTS(0.356 mm) (KSI)

under .008" DPH-KG 210-290 175 210-290 175 210-290 175 210-320 180(.203 mm) 2KG

Bend RadiusForming capability of a strip steel determines theseverity of bends it can withstand during partproduction. In order to avoid a borderline situa-tion where a tight bend might involve fracturing,the manufacturer can often increase the bendradius slightly and lessen the bending stressesgenerated.

At the specifying stage, it is the specification

writer’s responsibility to assure sufficient form-ability for required bends, by controlling striphardness and/or radii of bends.

Figure 5 gives minimum 90° bend radii for AISI1075 to 1095 steel strip of varying thickness andhardness; Figure 6 shows the relationship of hard-ness to minimum 90° radii for longitudinal andtransverse bends.

12

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FIGURE 5: Minimum 90° bend radii, AISI 1075 to 1095strip (transverse to direction of rolling)

Minimum radii, inches (mm)

FIGURE 6: Minimum 90° bend radii, AISI 1050 strip,longitudinal and transverse bends

13

Thickness: 0.035 - 0.070" Thickness: 0.015 - 0.035"(.89 - 1.78 mm) (.38 - .89 mm)

Multiplying FactorsRC Min. Max 30N Min Max.

43.0 10.0 15.8 64.0 10.0 15.843.5 10.4 16.2 64.5 10.9 16.744.0 10.9 16.6 65.0 11.5 17.244.5 11.1 16.9 65.5 11.8 17.445.0 11.6 17.3 66.0 12.2 18.045.5 11.9 17.8 66.5 12.8 18.646.0 12.2 18.1 67.0 13.1 19.146.5 12.8 18.6 67.5 13.9 19.747.0 13.1 19.1 68.0 14.0 20.147.5 13.6 19.5 68.5 14.8 20.748.0 14.0 20.1 69.0 15.0 21.048.5 14.4 20.3 69.5 15.8 21.749.0 14.9 20.8 70.0 16.0 22.049.5 15.3 21.3 70.5 16.4 22.450.0 15.8 21.8 71.0 16.8 22.750.5 16.2 22.1 71.5 17.2 23.151.0 16.8 22.7 72.0 17.8 23.751.5 17.2 23.1 72.5 18.1 24.052.0 17.8 23.7 73.0 18.4 24.352.5 18.1 24.1 73.5 18.7 24.653.0 18.8 24.5 74.0 19.1 25.253.5 19.1 25.154.0 19.8 25.6

Thickness: 0.010 - 0.014" Thickness: < 0.009"(.254 - .356 mm) (.23 mm)

Multiplying Factors15N Min. Max. DPH Min. Max. KSI82.0 10.0 15.7 423 10.0 14.0 20082.5 11.1 16.9 434 11.2 15.2 21083.0 12.1 18.1 458 12.2 16.0 22083.5 13.1 19.0 484 13.5 17.4 23084.0 13.5 19.4 498 14.5 18.5 24084.5 14.2 20.0 525 15.6 19.6 25085.0 15.0 21.0 544 16.6 20.7 26085.5 15.8 21.8 560 17.5 21.6 27086.0 16.8 22.6 577 18.5 22.6 28086.5 17.2 23.1 600 19.5 23.5 29087.0 18.2 24.1 615 20.5 24.6 30087.5 19.1 25.1 645 21.5 25.4 31088.0 19.8 25.6 675 22.2 26.4 32088.5 20.8 26.7 697 23.5 27.3 33089.0 21.2 27.089.5 21.8 27.590.0 22.1 28.0

TABLE 13: Hardness vs. approximate vise break of hardened and tempered high carbon steel strip

The following are limited to strip with a width to thicknessratio greater than 10:1.

EXAMPLE:Specified hardness:RC 48 to 50. Strip thickness: .045" (1.14 mm)STEP 1: Determine average hardness in example RC 49STEP 2: From table .035 to .070, RC 49 factors are 14.9(low) and 20.8 (high)STEP 3: Thickness .045 x low and high factors are.670"/.935" (17.02/23.75 mm) [range .265" (6.73 mm)]STEP 4: For limits more restrictive than thosedetermined in Step 3, contact Theis Precision Steel.

Radius of Bend: Number of Thicknesses (N1)6

5

4

3

2

1

0 30 32 34 36 38 40 42 44 46 48 50Hardness, RC

Longitudinal Bends

Transverse Bends

Strip Thickness0.060(1.524)

0.050(1.270)

0.040(1.016)

0.030(0.762)

0.020(0.508)

0.010(0.254) 40 42 44 46 48 50 52 54 56

Hardness, RC

0.200 (5.08)0.175 (4.45)

0.150 (3.81)0.125 (3.18)0.100 (2.54)

0.075 (1.91)

0.050 (1.27)


FIGURE 7: Photomicrographs of carbon strip steel at 1000x

FIGURE 8: Minimum bending radii for AISI 1050 martensiteand bainite; bend axis transverse to grain direction

ture, such as Theis BarcoForm, have a low hard-ness relative to grade, and therefore maximumductility for forming operations.

Permissible partial decarburization should bespecified in quantitative terms - that is, the depthbelow the surface to which carbon depletion mayextend. A recommended limit for general use is upto 2% of thickness, with “no free ferrite evident”.

For some applications, such as cyclic loadedparts, decarburization may affect fatigue strengthand shorten life due to lower surface strength. Inother applications where the strip edge becomesthe working part of the tool, the softness of adecarburized surface would be detrimental. Suchcases call for closer limitation by specifying abso-lute limits of partial decarburization allowed.

MICROSTRUCTUREReference to steel microstructure is not alwaysrequired in a specification. In the case of parts tobe stamped or blanked, pretempered strip may beselected in order to maintain uniformly closetolerances and avoid warpage during heat treat-ment. Pretempered material is usually hardened,quenched and tempered to a martensitic micro-structure.

If bends are also required during part produc-tion, proper manipulation of bend radius, angleto grain, hardness and analysis will usually providesufficient formability in pretempered strip.

However, in some cases with severe bends, ahigher degree of formability will be required thanthat offered by martensitic pretempered steel.Rather than automatically selecting annealed stock,the customer should consider strip with bainiticmicrostructure. Formability will be enhanced with-out sacrifice in dimensional stability or wear resis-tance.

Figure 8 illustrates the improved formability ofbainite over martensite. It indicates the minimumbending radii possible for given hardnesses ofbainitic and martensitic AISI 1050 material. Forexample, bainite hardened to Rc42 can be bentover a radius just twice its thickness (or greater)without breaking, whereas comparable marten-site strip requires a radius at least 3.4 times itsthickness for safe bending.

If even greater formability is required for sharppart bending, fully spheroidized annealed stripshould be specified. Steels with this microstruc-

14

5

4

3

2

1

30 32 34 36 38 40 42 44 46

Hardness, Rc

Rad

ius

of B

end

(N1)

Num

ber o

f Thi

ckne

sses

Martinsite

Bainite (Bartemp B)

Martensite BainitePinpoint Spheroidized

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TABLE 14: Standard finishesFinish Description

Scaleless Dark tight oxide film of varying bluetempered or gray color, result of liquid or block

quenching & tempering.Bright Non-oxidized surface, result oftempered controlled-atmosphere quenching

& tempering.Tempered Absolutely clean surface, result of& polished polishing after hardening & tempering.Tempered, Blue or straw surface color, result ofpolished & colored thermal treatment after polishing.(blue or straw)

SURFACE CONDITIONSurface ImperfectionsThe specification section on surface conditionusually begins with a statement about undesirablesurface imperfections. In many cases, this state-ment reads: “The surface must be free of scratches.It shall have no stress raisers, pits or seams.” Thisis a generalized statement which, if taken literally,constitutes overspecification. Strip with “no”surface imperfections can be produced only atgreat expense under laboratory-quality conditions.

A more realistic and economical approach is toconsider the effect of surface imperfections onthe finished part. This effect will be determinedby the configuration, direction, depth and sever-ity of the imperfections, and by the deflections,loads and stresses imposed on the part.

Usually, surface imperfections are not detri-mental if they are light and longitudinal, and ifstress concentrations are negligible. Thus, mini-mal stress raisers can often be tolerated.

Conversely, relative freedom from stress raisersis critical in circular parts that deflect in all direc-tions under load. Otherwise, application of loadand resultant deflection might cause fatigue prob-lems.

Type and depth of imperfection must be consid-ered. A sharp V-notch in some parts can causeearly fatigue failure in high loading situations. Inthe same circumstances, a shallow U-shaped notchmight prove much less sensitive.

Two types of flaws - seams and laminations - areusually detrimental to a part. They are the mostcommon cause of surface-related fatigue failure.Seams, slivers and laminations result from steel-making processes. A seam can be created, forexample, if foreign particles are trapped in thesteel ingot during pouring, or if the strip isscratched in hot rolling.

Specifying Surface RoughnessSurface roughness in high carbon strip is com-monly measured and specified in terms of RA(arithmetical average roughness) value. For non-critical applications, users frequently do not des-ignate an RA value. In these cases, cold-rolled andhardened strip will have a surface roughnessranging from 6-15 RA (the exact figure depends

on strip processing operations).Sometimes it is desirable to specify an RA value.

For example, manufacturers who require a mirrorbright finish on their parts might request stripwith an RA of 3-6. To convert RA to RMS, multiplyRA x 1.1 = RMS.

Measuring Surface ProfileTo measure surface roughness, a profilmeter isused. The profilometer’s sensitive stylus runs acrossthe width of the strip sample, recording surfacevariations in microns. An arithmetic average ofthese variations is displayed.

The profilometer can provide an average valueand an RA value, based on customer need forsurface texture requirements. We can also mea-sure scratch depth with the Rmd value.

FINISHA variety of finishes are available for both an-nealed and pretempered strip, with selection be-ing guided by finished part requirements. How-ever, for most strip applications finish is notsignificant, and the least expensive choice is thebest one.

When annealed strip is ordered, the standardfinish is No. 2 bright. This finish is so widelyaccepted that it is usually supplied automaticallywithout specification. This finish offers an aver-age reflectivity and surface roughness of 3-8 RA.

Four standard finishes are available forpretempered strip. They result naturally from thequench and tempering medium used for a givenstrip thickness. For most applications, the speci-fier will choose either scaleless and bright, ortempered, polished and colored- all of which can

15


FIGURE 9: Available edges for cold-rolled strip

be produced with an RA of 3-30. Maximum scratchdepth allowance is 1.0% depth of strip thickness.

A polished and colored surface is required evenless often than a polished surface. At one time,colored surfaces carried some significance be-cause they indicated the strip had received properheat treatment. Today, this finish is primarilycosmetic.

EDGESelection of edge configuration is dependent uponpart production processes and finished part con-tour. A number of edge shapes are available (Figure9); of these the most prevalent are No. 1 (squareand round), No. 3 (slit) and No. 5 (deburred).

No. 1 is an edge prepared to a specific contour-usually round or square. It entails a price pre-mium and should be the preferred choice when:• The edge is part of the finished product and

may affect appearance• The condition of the edge may affect fatigue in

application• A very accurate width is required• An edge suitable for electroplating or welding is

required

No. 3 is an approximately square edge pro-duced by slitting, with evidence of slitting frac-ture, burr, and toe-down (edge deformation).

No. 5 is a No. 3 edge with the burr removedthrough filing or similar method. Slitting fractureand toe-down will still be present.

Other edge configurations available are blunt,chamfered, beveled, and square with radius or bro-ken corners. When special edges are ordered, across-sectional sketch or detailed print of the de-sired contour should accompany the specification.

The variety of possible edges makes this a primearea for confusion during specifying. One pointto remember is that special edge configuration orpreparation entails added cost. The applicationshould always be considered first. For example, itwould be overspecifying to request a No. 1 edgewhen a part will be blanked between strip edges.

On the other hand, underspecifying would beinvolved if a user requested a No. 3 “with mini-mum burr.” This is a contradiction in terms as aNo. 3 edge has maximum burr. What is reallyneeded is a No. 1 or No. 5 edge.

SIZE TOLERANCESA basic step in order preparation is specifying

size and tolerances. Every application is unique inthat each has an optimum strip size with a compat-ible tolerance range. It is essential that tolerancesare expressed as equal values above and below anominal (target) dimension. In the use of Statisti-cal Process Control (SPC) techniques, it is alwaysbeneficial to aim for the center of the specifiedrange so the variations realized will be centered atthe nominal and be maintained well within limits.

Strip thickness and width should be given indecimal inches or millimeters. When cut lengthsare required instead of typical continuous coils,the length should be expressed in inches or feet(centimeters or meters). The use of gauge num-bers or fractional dimensions is less accurate, andtherefore undesirable.

In general, as strip width, thickness, or length in-creases, it is more difficult to hold close tolerances.ASTM has published widely accepted tolerances fordifferent widths and thicknesses. Table 16 listsTheis Precision Steel thickness tolerances which areconsiderably tighter than ASTM standards.

16

No. 1 EDGES

No. 3SLIT EDGE

No. 5 EDGE

SQUAREStandard

ROUNDStandard

BLUNT ROUNDStandard

BROKEN CORNERSSpecial

Maximum corner radius:0.003" (0.0762 mm)

BEVELSpecial

Deburredonly

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FIGURE 10: Control chart characteristic:Strip thickness

Target thickness: 7.10 Thickness values in mils (0.001 in)USL=0.80 LSL = -0.80x = 0.002 UCLx = 0.18 LCLX=-0.18R = 0.125 UCLR= 0.72 σ=0.054ZUSL = 14.88 ZLSL=-14.94 Zmin=14.88Cpk = 4.96 Total number of out of tolerance points: 0XI = 0.00 σi=0.056

X=ΣX/k R=ΣR/kUCLx=X+A2*R LCLx=X-A2*RUCLR=D4*R σ=R/d2

ZUSL=(USL-X)/σ ZLSL=(LSL-X)/σZmin=minimum of ZUSL or -ZLSL Cpk=Zmin/3n=5 k=50 A2=0.58 D4=2.11 d2=2.326Xi=ΣXi/N σi=SQRT((ΣXi

2-N*Xi2)/(N-1))When extra-close tolerances are required, de-

pending on the size and condition, additionalprocessing can be performed to achieve thesetighter tolerances (i.e. thickness tolerances of+/- .0001" [0.0025 mm] or width tolerances of+/- .0005" [0.0127 mm]).

Computer-assisted rolling millswith automated gaugingEvery major rolling mill in operation at TheisPrecision Steel utilizes state-of-the-art computercontrols. The systems are closed-loop, feed for-ward mass-flow control using non-contact gamma-ray gauges at the entry and exit of the mills. Thecomputer automatically adjusts the roll pressureto assure uniform thickness throughout the entirelength of the coil and maintain the tightest con-trols in the industry. Every coil which we produceoff our mills requires a minimum Cpk value. Eachmill can produce an SPC printout showing statis-tical and operational results (see Control Chart).These records are maintained on file within ourcomputer database and can be retrieved at anytime.

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TABLE 15: Width tolerances for cold rolled steelEdge Width Thickness Tolerancesno. in. (mm) in. (mm) +/- in. (mm)1 To 0.75 (19) incl <0.0938 (2.4) 0.003 (0.08)

Over 0.751 to 9.5 <0.125 (3.2) 0.004 (0.10)

(19.1 to 241) incl.3 0.094 to 14.0 To .025

(2.4 to 355) incl. (0.64) incl. 0.004 (0.10)0.375 to 14.0 Over .025

3 (9.5 to 355) incl. (0.64) to .068 0.005 (0.13)(1.7) incl.Over .068

3 0.5 to 14.0 (1.7) to .099 0.005 (0.13)(12.7 to 355) incl. (2.5) incl.

5 To 0.75 (1.90) incl. <0.0938 (0.24) 0.004 (0.10)5 Over 0.75 to 5.0

(19 to 127) incl. <0.125 (3.2) 0.005 (0.13)5 Over 5.0 to 9.0 .008 (0.02) to

(127 to 228) incl. .125 (3.2) incl. 0.005 (0.13)5 Over 9.0 to 14.0 .015 (038) to

(228 to 355) incl. .105 (2.7) incl. 0.005 (0.13)Tighter tolerances can be achieved. Consult your Theisrepresentative.

FIGURE 11: Exit thickness distribution

Length Deviation Percent of Total Length(ft) (pct) (mils) 0 10 20 30 40 50 60 70 80 90 100

0 0.00 0.00 0.00 0.00 0.00 0.01 0.02 0.0

14 0.2230 3.3

6478.0 93.6

162 2.325 0.47 0.10 0.01 0.00 0.00 0.00 0.00 0.0

-1.00-0.90-0.80-0.70-0.60-0.50-0.40-0.30-0.20-0.10

0.100.200.300.400.500.600.700.800.901.00

0 10 20 30 40 50 60 70 80 90 100

USL: 0.47 mils Zusl: 15.928LSL: -0.47 mils Zlsl: -15.899Cpk: 5.300 Zmin:15.899

SubgroupNumber R 0.0 +0.2 +0.4 +0.6 +0.8 x -0.2 -0.1 0.0 +0.1 +0.2

1 0.27 -0.012 0.46 -0.053 0.15 -0.014 0.08 -0.005 0.07

48 0.14 0.0249 0.11 -0.0450 0.12 -0.01

x UCL LCL x UCL


18

TABLE 16: Thickness Tolerances for Cold-Rolled Steel A,B

Width, inches (mm)Specified thickness Up to 3" (85 mm) 3" to 6" (85 to 170 mm) Over 6" to 14"

excl incl (170 to 397 mm) inclThickness tolerances in inches (mm) over and under

Under 0.010 (0.254) 0.0003 (0.008) 0.0003 (0.008) 0.0003 (0.008)0.010 to 0.015 (0.25 to 0.38) incl. 0.0004 (0.010) 0.0004 (0.010) 0.0004 (0.010)Over 0.015 to 0.020 (0.38 to 0.51) incl. 0.0005 (0.013) 0.0005 (0.013) 0.0005 (0.013)Over 0.020 to 0.030 (0.51 to 0.76) incl. 0.0005 (0.013) 0.0005 (0.013) 0.0005 (0.013)Over 0.030 to 0.040 (0.76 to 1.0) incl. 0.0008 (0.020) 0.0008 (0.020) 0.0010 (0.025)Over 0.040 to 0.070 (1.0 to 1.78) incl. 0.0010 (0.025) 0.0010 (0.025) 0.0012 (0.030)Over 0.70 to 0.100 (1.78 to 2.54) incl. 0.0012 (0.030) 0.0012 (0.030) 0.0015 (0.038)Over 0.100 to 0.125 (2.54 to 3.18) incl. 0.0015 (0.038) 0.0018 (0.046) 0.0020 (0.051)

A:Thickness measurements are taken 3/8 in. (9.5 mm) in from edge of strip, except on widths less than 1 in. (25 mm), the tolerancesare applicable for measurements at all locations.

B:Tighter tolerances can be achieved - consult your Theis representative.

OTHER TOLERANCESDepending upon the application, other dimen-sional characteristics may be very important to thesuccess of the processing and/or function of thefinished product. In these cases, it is important toinclude tolerances for these other attributes (suchas camber, crossbow, etc.).

The measurement technique utilized is criticalin achieving correlation of results between sup-plier and user. If a specific gauge or technique isused for measurement of a particular attribute, itis extremely helpful to pass this information along,so we can be more precise in our measurement ofyour specified tolerance.

FLATNESS (crossbow/concavity)Depending upon the application, users may alsoneed to specify flatness and camber. There are noindustry standards for flatness per ASTM. Astandard flatness tolerance used in the past was0.003 inches per inch (.076 mm/25.4 mm) ofstrip width (i.e. .003" PIW). This tolerance is notan accurate measure of flatness for the widerwidths, as flatness does not vary in direct propor-tion to the width. Flatness is best described as anarc (see Figure 12) and the flatness toleranceincreases exponentially. However, it is not alwaysa true arc and therefore is very difficult to utilizea standard formula. The type of edge, condition,thickness and width of material all play a role indetermining a suitable tolerance for flatness. Amore accurate determination for a No. 1 edge

material is one which uses the PIW formulas asshown in Table 17. Flatness on No. 3 and No. 5edge material will be slightly higher due to toe-

TABLE 17: Theis flatness/crossbows PIW formulas A,B

This table is applicable only forhardened and tempered with finished edge

Width in inches (mm)Specified Up to 1" 1 to 4" Over 4 to 9.5"thickness (25.4 mm) (25.4 to 101.6 mm) (101.6 to 241.3 mm)

inches (mm) excl. incl. incl.PIW flatness tolerances, in. (mm) maximum(Multiply actual width by value below)

Under 0.010 0.003 0.003 0.003(0.25) (0.08) (0.08) (0.08)

0.010 to 0.025 0.002 0.003 0.003(0.25 to 0.635) (0.05) (0.08) (0.08)

incl.Over

0.025 to 0.050 0.0015 0.002 0.003(0.635 to 1.27) (0.04) (0.05) (0.08)

incl.Over

0.050 to 0.125 0.001 0.0015 0.003(1.2 to 3.18) incl. (0.025) (0.04) (0.08)

A. Tolerances apply only to strip with No. 1 edgeB. For tighter tolerances, consult your Theis representative

FIGURE 12:Establishing cross bow limits with Theis flatness standard

Example: When strip width (W) is 2 inches (56 mm) maximum,maximum allowable arc height (A) is 0.006 inches (0.170 mm)

W

A

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19

FIGURE 13:Standard camber tolerances for strip 4 and 8 ft. long,

(1.22 m and 2.44 m)between 0.5 in. and 1.5 in. (12.7 and 38.1 mm) wide

(diagram exaggerated for emphasis)

PACKAGINGSpecification of packaging involves recognizingany particular limitations or requirements of thestrip user’s production and materials handlingequipment. Special instructions might involve coilcharacteristics such as inside and outside diam-eter, weight, and type of winding, or the coil

MAJOR SPECIFYING CRITERIA:To accurately fill your order to fit your exactrequirements, please supply as much of the fol-lowing data as is applicable:Scope: A general statement of purpose, including:

A ) Condition of steel strip: Cold rolled, skinpass, hardened, tempered, etc.

B) Application for which the product isintended.

Steel description: Name, type and steel gradenumber, e.g. AISI 1074M (TRM 34) or equivalent.Product form: Strip and coil size requirements.Nominal dimensions: Thickness and width withtolerances.Preferred edge condition: Number and style,e.g., #1 round, #5 deburred, #3 slit, etc.Surface finish and roughness: For instance,scaleless, bright polished or hard rolled with an Raof 15 max.Metallurgical requirements (if any): Specify de-carburization limits, inclusion limits, microstruc-ture (bainite, sorbite, etc.), any special heat treat-ments required.Other requirements: Specify in ranges anyhardness, tensile/elongation, bend, breakrequirements to be met.Samples: Include a drawing, part or materialwhich is acceptable.Packaging: Indicate skid, bundle, or tagrequirements. Specify any special packing, markingor rust preventative oil applications.Certification: Describe any test certificatesrequired for cast analysis and/or mechanicalproperties.Other: Describe any other special requirements andinclude any notes that will facilitate your order.

TABLE 18: Standard camber tolerancesStrip Standard Equivilent camber limits: in. (mm)width camber For various strip lengths: ft. (m)

W, tolerancein. Ct, in/ft

(mm) (mm/m)8 4 6 10 12 16 20

(2.44) (1.22) (1.83) (3.05) (3.66) (4.88) (6.09)

0.5-1.50 0.50 0.125 0.281 0.781 1.125 2.0 3.125(12.7-38.1) (12.7) (3.18) (7.14) (19.84) (28.58) (50.8) (79.38)

1.5-13.0 .25 .0625 0.141 0.391 0.563 1.0 1.562(38.1-330.2) (6.35) (1.59) (3.58) (9.93) (14.30) (25.4) (39.68)

down. In measuring flatness on slit material, it isimperative to remove any burr to eliminate theburr height from the flatness measurement.

CAMBER (edgebow or sweep)If camber is measured over a strip length notshown in Table 18, it can be easily converted to anequivalent value for comparison with the standardtolerance, using the formula:

Cu = Ck x (Lu / Lk)2where Cu = Unknown Camber

Ck = Known CamberLu = Unknown LengthLk = Known Length

packaging - skids, cartons, and other protectivemeasures. Any requirements that are outsidestandard mill practice should be identified in thepackaging section of the specification.

Coil ID (Standards - 12"/14"/16"/20"[300/350/400/500 mm])

Coil OD (Minimum/Maximum)Coil LengthCoil Set Requirement

For special requirements, please consult yourTheis representative.

W0.125"(3.18 mm)

0.5" (12.7 mm)4 ft.

(1.22 meters) 8 feet (2.44 meters)


TABLE 19: Typical Applications of Various TPS Grades of Steel

TRM 14 TRM 15 TRM 26 TRM 34 TRM 37 TRM 54 TRM 64 TRM 73 TRM 92 Welded• AISI 1050 • AISI 1527 • AISI 1065 • AISI 1074 • 1086 • AISI 1095 • BARCOID® • AISI 9262 • AISI 9260 • BAR-• DIN CK 55 • DIN CK 67 • DIN CK 75 • DIN CK 85 • DIN CK 101 • AISI W1C • DIN 67SiCr5 • JIS SUP 7 COMP®

• JIS S 50 C • JIS S 65 C • JIS S 70 C • JIS SK5 • JIS SK4 • JIS SK2• DIN 125W

• Clock • Belville springs washer• Power • Cantilever springs • Power

spring• Constant force spring• Retractor spring

• Putty knife • Tape steel- • Chain• Window measuring saw bar regulator tape• Trowels • Disposable• Hand saw utility knife

blade• Surgical blades• Trowels• Industrial knives• Hand hack• Filler gages

• Severely • Horn • Seat belt • Flapper formed diaphragm retractor valve springs • Piston ring • Shock

• Expander absorber steel • Thrust• Clutch washer cushion • Fuel injection

parts

• Scoring • Perforating • Doctor • Coater • Doctor rule die blade blade blade• Rotary • Cutting • Creping • Rotogravure die rule blade blade

• Leather • Leather • Leather splitting splitting splitting knife knife knife• Machete • Foam

splitting

• Wood • Wood • Metal • Friction • Bimetal cutting cutting cutting cutting saws• Meat/fish • Meat/fish cutting cutting

• Shuttle • Reed steel grip • Sinker • Sinkers• Heddle bar • Jacks

• Cylinder walls• Sliders

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