Drill Bolt And Anti Loosening Combination Screw

Machine Screws are uniformly threaded screws designed to be threaded into uniformly mating threaded Nuts (or threaded holes) in the parts they are intended to fasten. Typically available from micro sizes “00” (0.047) up to 3/8″ diameter (metric sizes also available). Shorter lengths are most common, but lengths can be up to 3″. Due to their relative size and strength, they can easily be differentiated from larger, stronger bolts. Additionally, driving (turning) the slotted or recessed head of the screw to tighten the fastening joint is common to machine screws.

A machine screw thread is defined by it thread size (diameter) and the number of threads per inch, followed by the thread form call out; “UNC” for coarse, “UNF” for fine, and the most common class of fit “2A” for external thread.

As the name implies, a machine screw is used to fasten various components together in machines, hand tools, white goods,  vehicles and many other applications. They are available in virtually any material, with the most common being steel, brass and stainless steel. The applicable standard is ANSI / AMSE B.18.6.3.