What grade are socket head cap screws?

Socket cap screws are often available in grade 12.9, meaning it has a UTS of 1200 MPa and will yield at 90% of this (1080 MPa).

Do you need washers with socket head cap screws?

The primary reason to not use a lock washer on a SHC is that they don’t work. The compressive load required to completely flatten a helical washer and turn it into a “flat” washer is only a very small % of the targeted preload for a SHC.

Do I have to use a washer with a screw?

Threaded fasteners stress the material in which they are driven. Driving a screw into wood, for example, may cause the wood to crack around the surface. Washers reduce the risk of such damage by evenly distributing the fastener’s load across the surface of the material. Not all materials require the use of washers.

What is a cap head screw?

A cap screw, by definition, is a machine bolt or screw that is threaded the to the cap and is normally fastened to a threaded hole rather than a nut. The picture of the “socket-head cap screw” accompanying this article would actually be a socket-head bolt, according to traditional definition.

What is hex cap screw?

A hex cap screw is a threaded fastener with a hexagonal-shaped head. While the term hex head screw is generally used interchangeably with hex bolt, these two fasteners are actually very different. Hex screws are typically smaller than hex bolts, but this is not always the case.

What is a hex head set screw?

Set screw or setscrew in the UK refers to a bolt which is fully threaded, with no smooth shank. These commonly have a hex head, but are also found with socket or screw heads. This contrasts with usage in the US where a set screw is almost universally a grub screw or small-headed bolt.

What are hex socket screws?

The hex socket screw, also known as the socket head cap screw, is a headed and externally threaded part designed for insertion through a close tolerance internally tapped hole and mated with a nut. Tension on the hex socket screw is induced by rotation of the screw head.