Hexagon socket countersunk head bolts and screws (Inch)

D A H J T
Nominal Size
 or Basic Screw 
Diameter
Head 
Diameter
Head
Height
Hexagon
Socket
Size
Key
Engagement
Theoretical Min Reference Tolerance Nom Min
1/4 0.2500 0.531 0.480 0.161 0.016 5/32 0.156 0.111
5/16 0.3125 0.656 0.600 0.198 0.017 3/16 0.188 0.135
3/8 0.3750 0.781 0.720 0.234 0.018 7/32 0.219 0.159
7/16 0.4375 0.844 0.781 0.234 0.018 1/4 0.250 0.159
1/2 0.5000 0.938 0.872 0.251 0.018 5/16 0.312 0.172
5/8 0.6250 1.188 1.355 0.324 0.022 3/8 0.375 0.220