BASIC
SCREW
DIAMETER |
DIAMETER |
A |
H |
FLUSH
TOLERANCE |
M |
T |
J |
Y |
BODY |
HEAD
DIAMETER |
HEAD
HEIGHT |
SPLINE
SIZE |
6 LOBE
SIZE |
SOCKET
SIZE |
KEY
ENGAGE |
DIAMETER |
max |
min |
min |
ref |
ref |
nom |
ref |
nom |
min |
0 |
0.0600 |
0.0600 |
0.0568 |
0.117 |
0.044 |
0.006 |
0.048 |
--- |
0.035 |
0.025 |
1 |
0.0730 |
0.0730 |
0.0695 |
0.143 |
0.054 |
0.007 |
0.060 |
--- |
0.050 |
0.031 |
2 |
0.0860 |
0.0860 |
0.0822 |
0.168 |
0.064 |
0.008 |
0.060 |
--- |
0.050 |
0.038 |
3 |
0.0990 |
0.0990 |
0.0949 |
0.193 |
0.073 |
0.010 |
0.072 |
--- |
1/16 |
0.044 |
4 |
0.1120 |
0.1120 |
0.1075 |
0.218 |
0.083 |
0.011 |
0.072 |
TX-9 |
1/16 |
0.055 |
5 |
0.1250 |
0.1250 |
0.1202 |
0.240 |
0.090 |
0.012 |
0.096 |
TX-10 |
5/64 |
0.036 |
6 |
0.1380 |
0.1380 |
0.1329 |
0.263 |
0.097 |
0.013 |
0.096 |
TX-15 |
5/64 |
0.066 |
8 |
0.1640 |
0.1640 |
0.1585 |
0.311 |
0.112 |
0.014 |
0.111 |
TX-20 |
3/32 |
0.076 |
10 |
0.1900 |
0.1900 |
0.1840 |
0.359 |
0.127 |
0.015 |
0.145 |
TX-25 |
1/8 |
0.087 |
1/4 |
0.2500 |
0.2500 |
0.2435 |
0.480 |
0.161 |
0.016 |
0.183 |
TX-30 |
5/32 |
0.111 |
5/16 |
0.3125 |
0.3125 |
0.3053 |
0.600 |
0.198 |
0.017 |
0.216 |
TX-40 |
3/16 |
0.135 |
3/8 |
0.3750 |
0.3750 |
0.3678 |
0.720 |
0.234 |
0.018 |
0.251 |
TX-45 |
7/32 |
0.159 |
7/16 |
0.4375 |
0.4375 |
0.4294 |
0.781 |
0.234 |
0.018 |
0.291 |
TX-50 |
1/4 |
0.159 |
1/2 |
0.5000 |
0.5000 |
0.4919 |
0.872 |
0.251 |
0.018 |
0.372 |
TX-50 |
5/16 |
0.172 |
5/8 |
0.6250 |
0.6250 |
0.6163 |
1.112 |
0.324 |
0.022 |
0.454 |
TX-55 |
3/8 |
0.220 |
3/4 |
0.7500 |
0.7500 |
0.7406 |
1.355 |
0.396 |
0.024 |
0.454 |
TX-60 |
1/2 |
0.220 |
7/8 |
0.8750 |
0.8750 |
0.8647 |
1.604 |
0.468 |
0.025 |
--- |
--- |
9/16 |
0.248 |
1" |
1.0000 |
1.0000 |
0.9886 |
1.841 |
0.540 |
0.028 |
--- |
--- |
5/8 |
0.297 |
It is not practical to make the edges of the flat
socket heads sharp, therefore a minimum head diameter is referenced
above. This is the minimum measurement allowed on flat sockets
with a rounded or flat edge on the countersink perimeter. The
flushness tolerance is the allowable distance between the top
of the screw and the surface of the countersink when a hole has
been countersunk exactly 82 ° .
Unfortunately there is not a handy formula available
to tabulate the minimum thread, grip and body length as with the
button socket cap screws. Your sales representative has this information
available.
