Countersunk flat head screws (common head style) with type H or Type Z Cross Recess - Product Grade A part 2 Steel Screws of Property Class 8.8, Stainless Steel Screws and Non - Ferrous Metal Screws ( Third Revision)
Countersunk Flat Head Screws (Common head Style) With Type H or Type Z Cross Recess - Product Grade A Part 1 Steel Screws of Property Class 4.8 ( Third Revision)
Technical supply conditions for threaded steel fasteners: Part 5 mechanical properties of fasteners made of carbon steel and alloy steel - Set screws and similar threaded fasteners with specified hardness classes - Coarse thread and fine pitch thread (Fourth Revision)