Socket Cap Screws - UNC - A2 Stainless Steel

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.

UNC (Unified National Coarse)

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

UNC (Unified National Coarse)

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