A2 Up to 20 210/30 500/73 Stainless steel minimum minimum with 17–19% 450/65 700/100 chromium and typical typical nickel ISO 3506-1 210/30 500/73 304 stainless steel-class 50 (annealed) ISO 3506-1 450/65 700/100 304 stainless steel-class 70 (cold worked) ISO 3506-1 600/87 800/120 304 stainless steel-class 80 Screw head shapes (a) pan, (b) button, (c) round, (d) truss, (e) flat (countersunk), (f) oval Combination flanged-hex/Phillips-head screw used in computers Pan head A low disc with outer edge Button or dome head Cylindrical with a rounded top Round head A dome-shaped head used for decoration. Truss head Lower-profile dome designed to prevent tampering Countersunk or flat head Conical, with flat outer face and tapering inner face allowing it to sink into the material. The angle of the screw is measured as the of the cone.
A2 Stainless steel with 17–19% chromium and nickel Up to 20 210/30 minimum 450/65 typical 500/73 minimum 700/100 typical ISO 3506-1 304 stainless steel-class 50 (annealed) 210/30 500/73 ISO 3506-1 304 stainless steel-class 70 (cold worked) 450/65 700/100 ISO 3506-1 304 stainless steel-class 80 600/87 800/120 Screw head shapes (a) pan, (b) button, (c) round, (d) truss, (e) flat (countersunk), (f) oval Combination flanged-hex/Phillips-head screw used in computers Pan head A low disc with outer edge Button or dome head Cylindrical with a rounded top Round head A dome-shaped head used for decoration. Truss head Lower-profile dome designed to prevent tampering Countersunk or flat head Conical, with flat outer face and tapering inner face allowing it to sink into the material. The angle of the screw is measured as the of the cone.