This table contains dimensions of round headed machine screws ranging in thread size from 0 to 3/4 inch nominal diameter.
This table includes maximum and minimum
screw head diameter and height, slot width and depth as well as maximum screw
shaft diameter information.
NOTES: All dimensions are in inches.
Head dimensions for sizes 7/16 in and larger are in agreement with round-head
cap screw dimensions except the minimum values have been decreased to provide
tolerances in proportion to balance of table. The diameter of the unthreaded
portion of machine screws shall not be less than the minimum pitch diameter
nor more than the maximum major diameter of the thread. The radius of the fillet
at the base of the head shall not exceed one- half the pitch of the screw thread.
D
A H
J T
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Max
Head Diameter Height of head Width of slot Depth of slot
Nominal diameter ------------- -------------- ------------- -------------
size of screw Max Min
Max Min Max Min
Max Min
------- -------- ----- ----- ----- ----- -----
----- ----- -----
0 0.060 0.113 0.099
0.053 0.043 0.023 0.016 0.039 0.029
1 0.073 0.138 0.122
0.061 0.051 0.026 0.019 0.044 0.033
2 0.086 0.162 0.146
0.069 0.059 0.031 0.023 0.048 0.037
3 0.099 0.187 0.169
0.078 0.067 0.035 0.027 0.053 0.040
4 0.112 0.211 0.193
0.086 0.075 0.039 0.031 0.058 0.044
5 0.125 0.236 0.217
0.095 0.083 0.043 0.035 0.063 0.047
6 0.138 0.260 0.240
0.103 0.091 0.048 0.039 0.068 0.051
8 0.164 0.309 0.287
0.120 0.107 0.054 0.045 0.077 0.058
10 0.190 0.359 0.334
0.137 0.123 0.060 0.050 0.087 0.065
12 0.216 0.408 0.382
0.153 0.139 0.067 0.056 0.096 0.072
1/4 0.250 0.472 0.443
0.175 0.160 0.075 0.064 0.109 0.082
5/16 0.3125 0.590 0.557 0.216
0.198 0.084 0.072 0.132 0.099
3/8 0.375 0.708 0.670
0.256 0.237 0.094 0.081 0.155 0.117
7/16 0.4375 0.750 0.707 0.328
0.307 0.094 0.081 0.196 0.148
1/2 0.500 0.813 0.766
0.355 0.332 0.106 0.091 0.211 0.159
9/16 0.5625 0.938 0.887 0.410
0.385 0.118 0.102 0.242 0.183
5/8 0.625 1.000 0.944
0.438 0.411 0.133 0.116 0.258 0.195
3/4 0.750 1.250 1.185
0.547 0.516 0.149 0.131 0.320 0.242
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