5133-00-239-0783 (B94.2)
NSN 5133-00-239-0783 (NIIN 00-239-0783) is a countersink in Federal Supply Class 5133, Drill Bits, Counterbores, And Countersinks: Hand And Machine — an angular cutting tool, usually made with angular relief, having one or more flutes with specific size angle cutting edges. Manufacturer part number B94.2 (The American Society Of Mechanical, CAGE 05047); also referenced as GGG-C-613 TY4CLBSZ7/8 (General Services Administration); GGG-C-613 (Federal Specifications Promulgated).
Key specs: 40 rockwell c minimum and 53 rockwell c maximum hardness; full characteristics table below. NIIN assigned January 1963; DEMIL A (none required); export Schedule B 8205.10.0000.