Flat point socket set screws BS 2470
ASTM A193 Grade B7 Specifications
ASTM A193 Grade B7 Specifications
| Nominal Size or Basic Screw Diameter | D | J | K | Shortest nominal length to which dimension K applies | C | |
|---|---|---|---|---|---|---|
| Basic screw diameter | Hexagon Socket Size | Key Engagement | Flat point | |||
| Flat Points | ||||||
| Nom. | Min. | Max. | Min. | |||
| 0 | 0.0600 | 0.028 | 0.022 | 1/16 | 0.033 | 0.027 |
| 1 | 0.0730 | 0.035 | 0.028 | 3/32 | 0.040 | 0.033 |
| 2 | 0.0860 | 0.035 | 0.028 | 3/32 | 0.047 | 0.039 |
| 3 | 0.0990 | 0.050 | 0.040 | 3/32 | 0.054 | 0.045 |
| 4 | 0.1120 | 0.050 | 0.040 | 1/8 | 0.061 | 0.051 |
| 5 | 0.1250 | 1/16 | 0.050 | 1/8 | 0.067 | 0.057 |
| 6 | 0.1380 | 1/16 | 0.050 | 3/16 | 0.074 | 0.064 |
| 8 | 0.1640 | 5/64 | 0.062 | 3/16 | 0.087 | 0.076 |
| 10 | 0.1900 | 3/32 | 0.075 | 3/16 | 0.102 | 0.088 |
| 1/4 | 0.2500 | 1/8 | 0.100 | 1/4 | 0.132 | 0.118 |
| 5/16 | 0.3125 | 5/32 | 0.125 | 5/16 | 0.172 | 0.156 |
| 3/8 | 0.3750 | 3/16 | 0.150 | 3/8 | 0.212 | 0.194 |
| 7/16 | 0.4375 | 7/32 | 0.175 | 7/16 | 0.252 | 0.232 |
| 1/2 | 0.5000 | 1/4 | 0.200 | 1/2 | 0.291 | 0.270 |
| 5/8 | 0.6250 | 5/16 | 0.250 | 5/8 | 0.371 | 0.347 |
| 3/4 | 0.7500 | 3/8 | 0.300 | 3/4 | 0.450 | 0.425 |
| 7/8 | 0.8750 | 1/2 | 0.400 | 7/8 | 0.530 | 0.502 |
| 1 | 1.0000 | 9/16 | 0.450 | 1 | 0.609 | 0.579 |
| Nominal Socket Size | J | e | |
|---|---|---|---|
| Socket width across flats | Width across corners | ||
| Max. | Min. | Min. | |
| 0.028 | 0.0285 | 0.0280 | 0.032 |
| 0.035 | 0.0355 | 0.0350 | 0.040 |
| 0.050 | 0.0510 | 0.0500 | 0.057 |
| 1/16 | 0.0635 | 0.0625 | 0.071 |
| 5/64 | 0.0791 | 0.0781 | 0.089 |
| 3/32 | 0.0952 | 0.0937 | 0.107 |
| 1/8 | 0.1270 | 0.1250 | 0.143 |
| 5/32 | 0.1587 | 0.1562 | 0.178 |
| 3/16 | 0.1900 | 0.1875 | 0.214 |
| 7/32 | 0.2217 | 0.2187 | 0.250 |
| 1/4 | 0.2530 | 0.2500 | 0.285 |
| 5/16 | 0.3160 | 0.3125 | 0.357 |
| 3/8 | 0.3790 | 0.3750 | 0.429 |
| 1/2 | 0.5050 | 0.5000 | 0.571 |
| 9/16 | 0.5680 | 0.5625 | 0.643 |
| 5/8 | 0.6310 | 0.6250 | 0.715 |
NOTE 1:Applicable socket depths are specified in the dimensional tables and notes for the
respective screw types.
NOTE 2:For brosched sockets which are at or near the maximum limit of size, it is essential
that the overcut resulting from drilling does not exceed 20% of the length of any flat of the socket.
NOTE 3:Where hexagon sockets are chamfered the depth of chamfer ought not to exceed 10% of the
nominal socket size for sizes up to and including 1/16 and 7.5% for larger sizes.
