Dog 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 | P | Q | ||
|---|---|---|---|---|---|---|---|---|
| Basic screw diameter | Hexagon Socket Size | Key Engagement | Dog point | Half dog point | ||||
| Diameter | Length | |||||||
| Nom. | Min. | Max. | Min. | Max. | Min. | |||
| 0 | 0.0600 | 0.028 | 0.022 | 3/32 | 0.040 | 0.037 | 0.017 | 0.013 |
| 1 | 0.0730 | 0.035 | 0.028 | 3/32 | 0.049 | 0.045 | 0.021 | 0.017 |
| 2 | 0.0860 | 0.035 | 0.028 | 1/8 | 0.057 | 0.053 | 0.024 | 0.020 |
| 3 | 0.0990 | 0.050 | 0.040 | 1/8 | 0.066 | 0.062 | 0.027 | 0.023 |
| 4 | 0.1120 | 0.050 | 0.040 | 1/8 | 0.075 | 0.070 | 0.030 | 0.026 |
| 5 | 0.1250 | 1/16 | 0.050 | 3/16 | 0.083 | 0.078 | 0.033 | 0.027 |
| 6 | 0.1380 | 1/16 | 0.050 | 3/16 | 0.092 | 0.087 | 0.038 | 0.032 |
| 8 | 0.1640 | 5/64 | 0.062 | 3/16 | 0.109 | 0.103 | 0.043 | 0.037 |
| 10 | 0.1900 | 1/4 | 0.075 | 1/4 | 0.127 | 0.120 | 0.049 | 0.041 |
| 1/4 | 0.2500 | 1/8 | 0.100 | 5/16 | 0.156 | 0.149 | 0.067 | 0.059 |
| 5/16 | 0.3125 | 5/32 | 0.125 | 3/8 | 0.203 | 0.195 | 0.082 | 0.074 |
| 3/8 | 0.3750 | 3/16 | 0.150 | 7/16 | 0.250 | 0.241 | 0.099 | 0.089 |
| 7/16 | 0.4375 | 7/32 | 0.175 | 1/2 | 0.297 | 0.287 | 0.114 | 0.104 |
| 1/2 | 0.5000 | 1/4 | 0.200 | 5/8 | 0.344 | 0.334 | 0.130 | 0.120 |
| 5/8 | 0.6250 | 5/16 | 0.250 | 3/4 | 0.469 | 0.456 | 0.164 | 0.148 |
| 3/4 | 0.7500 | 3/8 | 0.300 | 7/8 | 0.562 | 0.549 | 0.196 | 0.180 |
| 7/8 | 0.8750 | 1/2 | 0.400 | 1 | 0.656 | 0.642 | 0.227 | 0.211 |
| 1 | 1.0000 | 9/16 | 0.450 | 11/4 | 0.750 | 0.734 | 0.260 | 0.240 |
| 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.
