A machine screw is a type of screw that is commonly used in industrial and manufacturing applications to secure components within engines, electronic products and general machinery.
This type of machine screw has a raised head with a slotted recess that can be installed with a flat-bladed screwdriver or bit. They are available in zinc plated, brass or stainless steel.
Unlike the domed head of the pozidrive version, slotted pan head machine screws have a head that is flat on top, resembling an upturned frying pan. For a similar type of screw that has a slightly smaller diameter but with a thicker, deeper head take a look at our cheese head slotted machine screws.
About UNF Thread
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.
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