Flat head socket countersunk screw, high tensile , self colour. BS 2470 Class Fit 3A ASME/ANSI B18.3 1986. Hardness RC36/43 The countersunk flush finish and hexagon drive is ideal for a high torque attractive finish.
UNF 1 Socket Countersunk Screw Technical Specification:
Screw Diameter - 0.073
(D) Body Diameter - 0.071
(A) Head Diameter (Theoretical Sharp max) - 0.168
Head Diameter ( ABS Min) - 0.143
(H) Head Height (Reference) - 0.054
Head Height (Flushness Tolerance) - 0.007
(J) Hexagon Socket Size - 0.050
(T) Key Engagement - 0.031
(F) Fillet Extensions - 0.008