allowable stresses for bolts
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Akkowable stress for boltsTRANSCRIPT
ALLOWABLE STRESSES AND LOADS FOR BOLTS OF GRADE 8.8 (AS PER IS 800:1984)
1.MULTIPLYING RATIOS CALCULATION FOR AXIAL TENSION AND SHEARFOR GRADE 8.8 BOLTS
ULTIMATE TENSILE STRENGTH (Fu) 800 MpaYIELD STREGTH (Fy) 640 Mpa
multiplying ratio = (X/235) = 2.38 VALUE OF X : MIN OF
1. Fy 640 Mpa2. 0.7 Fu 560 Mpa
2.MAX PERMISSIBLE VALUES FOR BOLTS
FOR GRADE 4.6 (VALUES FROM TABLE 8.1 OF IS 800:1984) FOR GRADE 8.8(CALCULATED AS PER CLAUSE 8.9.4.3 )
DESCRIPTION OF FASTENERS CLEAR TOLERANCE & TURNED BOLTS BOLTS IN CLEARANCE HOLES CLEAR TOLERANCE & TURNED BOLTS BOLTS IN CLEARANCE HOLES
AXIAL TENSION ALL 120 120 286 286VALUES
SHEAR IN 100 80 238 191MEGA
BEARING PASCALS 300 250 715 596
3. ALLOWABLE LOAD VALUES
DIAMETER OF BOLTS (IN MM) 16 20 24 30 32
AXIAL TENSION ALL 57 90 129 202 230VALUES
SHEAR IN 48 75 108 108 192KILO
BEARING NEWTONS 144 225 323 323 575
AS PER AISC-89, FOR GRADE 8.8 BOLTSALLOWABLE TENSILE STRESS (0.33xFu) 26.4 KN/sq cmALLOWABLE SHEAR STRESS (0.2 Fu) 16.3 KN/sq cm
nominal stress values as per AISC-05 (refer chapter 16 page 104 ,table J3.2) for grade 8.8 bolts
for threads to be included in the shear planeFu = 800 n/mm2
nominal tensile stress = 0.75 * Funominal shear stress = 0.4*Fu
allowable strenght = nominal strength / WW - safety factor
ALLOWABLE TENSILE STRESS = 0.38*Fu 304ALLOWABLE SHEAR STRESS = 0.2*Fu 160
264 MPa163 MPa
nominal stress values as per AISC-05 (refer chapter 16 page 104 ,table J3.2) for grade 8.8 bolts
ALLOWABLE STRESSES FOR HIGH STRENGTH BOLTS (AS PER AISC 360-05)
SIZE OF BOLT LENGTH THREAD Atp Ashank NOMINAL STRESS VALUES(MP a) ALLOWABLE STRESS VALUES(MP a) ALLOWABLE LOADS(KN)BOLT DIA (D mm) (L mm) LENGTH(T mm) TENSILE SHEAR TENSILE SHEAR TENSILE SHEARM12X30 12 30 30 1130 1130 800 320 400 160 45 18M12X40 12 40 40 1507 1507 800 320 400 160 45 18M16X55 16 55 47 2361 2763 684 320 342 160 69 32M20X55 20 55 45 2826 3454 655 320 327 160 103 50M20X70 20 70 55 3454 4396 629 320 314 160 99 50M24X65 24 65 50 3768 4898 615 320 308 160 139 72M24X85 24 85 70 5275 6406 659 320 329 160 149 72M24X95 24 95 60 4522 7159 505 320 253 160 114 72
M30X120 30 120 90 8478 11304 600 320 300 160 212 113M36X120 36 120 90 10174 13565 600 320 300 160 305 163
Atp - area of threaded portionAshank - area of shank