Hex Set Screws - UNF - A2 Stainless Steel

Hexagon set screws, or hex sets to give them their common name, are available in both metric and imperial thread sizes in a wide range of finishes. A set screw differs from a bolt in that the shank is threaded all the way from the tip to the head.

UNF stands for Unified National Fine. It is a common imperial thread type with more threads per axial distance than its UNC equivalent.

Unified thread types (UNF and UNC) were introduced at the beginning of World War 2 to enable the interchangeability of machinery manufacturing between the USA, Canada and Great Britain. Still commonly found on a vast array of old machines and vehicles in the UK, UNF and UNC threads continue to be the standard thread in the USA and Canada.

A2 stainless steel is often referred to as 304 or 18/8 Stainless. 18/8 actually refers to the amount of chromium and nickel in the alloy - 18% chromium and 8% nickel.

A2 stainless is the most common type of steel used for the manufacture of fasteners and is suitable for general use.