Singer sewing machine screw threads and taps- machine screw thread types ,Singer Sewing Machine Screw Threads There is often confusion about the various screw threads used on Singer sewing machines. When production was first started there were no national or international standards for manufacturing and so companies like Singer used whatever diameters and thread pitches they felt were convenient for them.What Is a Machine Screw? | HunkerMachine screws are versatile in the number of types of joints they can fasten. They can be used for fastening two or more components with through holes and a nut behind all the components. They can be passed through two or more components and then finally threaded into the rearmost component, which is solid and uniformly threaded and acts as the nut in the joint.