MACHINE SCREWS
INDENTED HEX WASHER HEAD 
HEAD DIMENSIONS
All Dimensions in Inches
Basic 
Screw 
Diameter
Width 
Across 
Flats
Width 
Across
 Corners
Head 
Height
Diameter of 
Washer
Thickness of 
Washer
Max. Min. Min. Max. Min. Max. Min. Max. Min.
4/40 .187 .181 .202 .060 .049 .243 .225 .019 .011
5/40 .187 .181 .202 .070 .058 .260 .240 .0.25 .015
6/32 .250 .244 .272 .093 .080 .328 .302 .0.25 .015
8/32 .250 .244 .272 .110 .096 .348 .322 .031 .019
10/24 .312 .305 .340 .120 .105 .414 .384 .031 .019
10/32 .312 .305 .340 .120 .105 .414 .384 .031 .019
12/24 .312 .305 .340 .155 .139 .432 .398 .039 .022
1/4 .375 .367 .409 .190 .172 .520 .480 .050 .030
5/16 .500 .489 .545 .230 .208 .676 .624 .055 .035
3/8 .562 .551 .614 .295 .270 .780 .720 .063 .037