United States Standard thread (USS thread), also known as Sellers Standard thread,[1] Franklin Institute thread[1] and American Standard thread,[2] is a standard for inch based threaded fasteners and washers.[3]
The USS standard is no longer supported. It, together with the SAE fastener standard, was incorporated into the Unified Thread Standard. However, the term, USS, continues to be used occasionally today to describe inch based threaded fasteners with a coarse thread pitch and inch based washers that are a little bit larger than the corresponding SAE washer. The Unified Thread Standard uses the term UNC (Unified Coarse) to describe a fastener that previously would have been designated USS and UNF (Unified Fine) to describe a fastener that would have previously been designated SAE.
- ^ a b Adt, Howard (1920). Screw Thread Production to Close Limits. p. 7. Retrieved 2009-01-16.
- ^ "History of screw threads". Retrieved 2011-04-24.
- ^ "Uses, Benefits, and Applications of Coach Screws". Fixabolt. 2023-02-26. Retrieved 2023-07-25.