What is High Tensile Bolts?

Understanding High Tensile Bolts/Fasteners Grades.

Engineers, construction, automobile, manufacturing and a lot of services industry professionals know the answer to this and many other technical questions about fasteners and fixings.

But a lot of us have questions, what are these numbers on some fasteners and fixings we come across in our garage, some furniture and other household stuff.Before we answer what is high tensile bolts, here are a few things you need to know about fasteners and fixings or bolts.

Go to following slides and find out…

Commonly, most of us know fasteners as bolts, screws or studs.

So what is the difference between a bolt, screw and stud?

What is a Nut & Bolt?The threaded rod that you see in this picture is a bolt

Alongside is a nut and it is often mated with a bolt.

What is a Screw?A screw is slightly different than a bolt.Screws are externally threaded fasteners. Screws have the ability of forming it’s own thread when inserted into the holes inside assembled parts.

What is a Stud?Stud is different from both bolt and screw in appearance and uses. It does not have head at one end like a normal fastener. Studs are metal rods or you could say shafts with threads on both sides or both ends.

So what are those numbers that we see in most of the fasteners?

These numbers on fasteners and fixings represent the ultimate tensile strength of a bolt.

In Australia, there are 3 different grades of bolts in common use.

Commercial GradeStructural GradeHigh Tensile

Commercial Grade:This is the lowest grade with a tensile strength of 4.6 or 400 MPa.

Structural Grade:Structural grade comes next with a tensile strength of around 800 MPa or 8.8.

High TensileHigh tensile bolts are the highest grade with an ultimate tensile strength of 1200 MPa or 12.9

Presentation of THE WDS GROUP.

Australia’s one stop specialised fastener and fixings specialist.