Heli-Coil
drilling data - inch
INCH - DRILLED HOLE DIMENSIONS
Suggested Drill Size Nominal
Thread size
Aluminum
Steel,Magnesium,Plastic
UNIFIED COARSE
1 (.073)-64 #47 (.0785) #46 (.0810)
2 (.086)-56 3/32 (.0938) #41 (.0960)
3 (.099)-48 #36 (.1065) 7/64 (.1094)
4 (.112)-40 #31 (.1200) #31 (.1200)
5 (.125)-40 3.4mm (.1339) #29 (.1360)
6 (.138)-32 #26 (.1470) #25 (.1495)
8 (.164)-32 #17 (.1730) #16 (.1770)
10 (.190)-24 13/64 (.2031) #5 (.2055)
12 (.216)-24 #1 (.2280) #1 (.2280)
1/4 (.2500)-20 H (.2660) H (.2660)
5/16 (.3125)-18 Q (.3320) Q (.3320)
3/8 (.3750)-16 X (.3970) X (.3970)
7/16 (.4375)-14 29/64 (.4531) 29/64 (.4531)
1/2 (.5000)-13 33/64 (.5156) 17/32 (.5312)
9/16 (.5625)-12 37/64 (.5781) 19/32 (.5938)
5/8 (.6250)-11 21/32 (.6562) 21/32 (.6562)
3/4 (.7500)-10 25/32 (.7812) 25/32 (.7812)
7/8 (.8750)-9 29/32 (.9062) 29/32 (.9062)
1 (1.000)-8 1-1/32 (1.0312) 1-1/32 (1.0312)
1-1/8 (1.1250)-7 1-11/64 (1.1719) 1-11/64 (1.1719)
1-1/4 (1.2500)-7 1-19/64 (1.2969) 1-19/64 (1.2969)
1-3/8 (1.3750)-6 1-27/64 (1.4219) 1-27/64 (1.4219)
1-1/2 (1.5000)-6 1-35/64 (1.5469) 1-35/64 (1.5469)
UNIFIED FINE
2 (.086)-64 2.35mm (.0925) 2.35mm (.0925)
3 (.099)-56 #37 (.1040) #36 (.1065)
4 (.112)-48 3mm (.1181) #31 (.1200)
6 (.138)-40 #26 (.1470) #25 (.1495)
8 (.164)-36 #17 (.1730) #16 (.1770)
10 (.190)-32 #7 (.2010) 13/64 (.2031)
1/4 (.2500)-28 G (.2610) 6.7mm (.2638)
5/16 (.3125)-24 21/64 (.3281) 21/64 (.3281)
3/8 (.3750)-24 25/64 (.3906) 25/64 (.3906)
7/16 (.4375)-20 29/64 (.4531) 29/64 (.4531)
1/2 (.5000)-20 33/64 (.5156) 33/64 (.5156)
9/16 (.5625)-18 37/64 (.5781) 37/64 (.5781)
5/8 (.6250)-18 41/64 (.6406) 41/64 (.6406)
3/4 (.7500)-16 49/64 (.7656) 49/64 (.7656)
7/8 (.8750)-14 57/64 (.8906) 57/64 (.8906)
1 (1.000)-14 1-1/64 (1.0156) 1-1/32 (1.0312)
1 (1.000)-12 1-1/64 (1.0156) 1-1/32 (1.0312)
1-1/8 (1.1250)-12 1-9/64 (1.1406) 1-5/32 (1.1562)
1-1/4 (1.2500)-12 1-17/64 (1.2656) 1-9/32 (1.2812)
1-3/8 (1.3750)-12 1-25/64 (1.3906) 1-13/32 (1.4062)
1-1/2 (1.5000)-12 1-33/64 (1.5156) 1-17/32 (1.5312)
Heli-Coil
thread data - inch
Pitch Diameter
3B 2B
Minor
Diameter
Nominal
Thread Size
Min.
Max. Max. Min. Max.
Max.
Major
Diameter
Thread
Pitch
UNIFIED COARSE
1 (.073)-64 .0832 .0843 .0850 .0764 .0823 .0958 .01563
2 (.086)-56 .0976 .0989 .0996 .0899 .0961 .1117 .01786
3 (.099)-48 .1126 .1140 .1148 .1036 .1104 .1289 .02083
4 (.112)-40 .1283 .1299 .1308 .1175 .1252 .1473 .02500
5 (.125)-40 .1413 .1430 .1438 .1305 .1373 .1603 .02500
6 (.138)-32 .1583 .1601 .1611 .1448 .1527 .1817 .03125
8 (.164)-32 .1843 .1862 .1872 .1708 .1781 .2077 .03125
10 (.190)-24 .2170 .2192 .2203 .1990 .2080 .2475 .04167
12 (.216)-24 .2430 .2453 .2464 .2250 .2340 .2735 .04167
1/4 (.2500)-20 .2825 .2851 .2864 .2608 .2704 .3187 .05000
5/16 (.3125)-18 .3486 .3515 .3529 .3245 .3342 .3884 .05556
3/8 (.3750)-16 .4156 .4189 .4203 .3885 .3987 .4602 .06250
7/16 (.4375)-14 .4839 .4875 .4890 .4530 .4639 .5343 .07143
1/2 (.5000)-13 .5499 .5537 .5554 .5166 .5273 .6042 .07692
9/16 (.5625)-12 .6167 .6208 .6225 .5806 .5918 .6751 .08333
5/8 (.65250)-11 .6841 .6885 .6903 .6447 .6564 .7477 .09091
3/4 (.7500)-10 .8149 .8196 .8216 .7716 .7838 .8850 .10000
7/8 (.8750)-9 .9471 .9522 .9543 .8990 .9119 1.0247 .11111
1 (1.000)-8 1.0812 1.0868 1.0890 1.0271 1.0421 1.1681 .12500
1-1/8 (1.1250)-7 1.2178 1.2239 1.2262 1.1559 1.1730 1.3171 .14286
1-1/4 (1.2500)-7 1.3428 1.3490 1.3514 1.2809 1.2980 1.4421 .14286
1-3/8 (1.3750)-6 1.4832 1.4900 1.4926 1.4110 1.4310 1.5982 .16667
1-1/2 (1.5000)-6 1.6082 1.6151 1.6177 1.5360 1.5560 1.7232 .16667
UNIFIED FINE
2 (.086)-64 .0962 .0974 .0981 .0894 .0947 .1088 .01563
3 (.099)-56 .1106 .1119 .1126 .1029 .1086 .1247 .01786
4 (.112)-48 .1256 .1271 .1279 .1166 .1229 .1419 .02083
6 (.138)-40 .1543 .1560 .1569 .1435 .1503 .1733 .02500
8 (.164)-36 .1821 .1840 .1849 .1701 .1771 .2032 .02778
10 (.190)-32 .2103 .2123 .2133 .1968 .2041 .2337 .03125
1/4 (.2500)-28 .2732 .2754 .2765 .2577 .2646 .2995 .03571
5/16 (.3125)-24 .3395 .3421 .3433 .3215 .3288 .3700 .04167
3/8 (.3750)-24 .4020 .4047 .4059 .3840 .3910 .4325 .04167
7/16 (.4375)-20 .4700 .4731 .4744 .4483 .4561 .5062 .05000
1/2 (.5000)-20 .5325 .5357 .5371 .5108 .5186 .5687 .05000
9/16 (.5625)-18 .5986 .6020 .6035 .5745 .5826 .6384 .05556
5/8 (.6250)-18 .6611 .6646 .6661 .6370 .6451 .7009 .05556
3/4 (.7500)-16 .7906 .7945 .7961 .7635 .7720 .8352 .06250
7/8 (.8750)-14 .9214 .9257 .9274 .8905 .8994 .9718 .07143
1 (1.000)-14 1.0464 1.0508 1.0527 1.0155 1.0243 1.0968 .07143
1 (1.000)-12 1.0542 1.0589 1.0608 1.0181 1.0281 1.1126 .08333
1-1/8 (1.1250)-12 1.1792 1.1841 1.1860 1.1431 1.1531 1.2376 .08333
1-1/4 (1.2500)-12 1.3042 1.3092 1.3112 1.2681 1.2781 1.3626 .08333
1-3/8 (1.3750)-12 1.4292 1.4343 1.4364 1.3931 1.4031 1.4876 .08333
1-1/2 (1.5000)-12 1.5542 1.5595 1.5615 1.5181 1.5281 1.6126 .08333
Heli-Coil
drilling data - metric
METRIC - DRILLED HOLE DIMENSIONS
Minor Diameter Suggested Drill Size Nominal
Thread Size
Min. Max.
Aluminum Steel, Magnesium ,Plastic
METRIC COARSE
M2X0.4 2.087 2.170 2.1 2.1
M2.2x0.45 2.297 2.397 2.3 2.35
M2.5x0.45 2.597 2.697 2.55 2.65
M3x0.5 3.108 3.220 3.15 3.2
M3.5x0.6 3.630 3.755 3.7 3.7
M4x0.7 4.152 4.292 4.2 4.25
M5x0.8 5.174 5.334 5.2 5.3
M6x1 6.217 6.407 6.25 6.3
M7x1 7.217 7.407 7.25 7.3
M8x1.25 8.271 8.483 8.3 8.4
M10x1.5 10.324 10.560 10.5 10.5
M12x1.75 12.379 12.644 12.5 12.5
M14x2 14.433 14.733 14.5 14.5
M16x2 16.433 16.733 16.5 16.5
M18x2.5 18.541 18.896 18.75 18.75
M20x2.5 20.541 20.896 20.75 20.75
M22x2.5 22.541 22.896 22.75 22.75
M24x3 24.649 25.049 24.75 24.75
M27x3 27.649 28.049 27.75 27.75
M30x3.5 30.757 31.207 31 31
M33x3.5 33.757 34.207 34 34
M36x4 36.866 37.341 37 37
M39x4 39.866 40.341 40 40
METRIC FINE
M8x1 8.217 8.407 8.25 8.3
M10x1 10.217 10.407 10.25 10.25
M10x1.25 10.271 10.483 10.25 10.25
M12x1.25 12.271 12.483 12.25 12.25
M12x1.5 12.324 12.560 12.25 12.5
M14x1.5 14.324 14.560 14.25 14.5
M16x1.5 16.324 16.560 16.25 16.5
M18x1.5 18.324 18.560 18.25 18.5
M20x1.5 20.324 20.560 20.25 20.5
M22x1.5 22.324 22.560 22.25 22.5
M18x2 18.433 18.733 18.5 18.5
M20x2 20.433 20.733 20.5 20.5
M22x2 22.433 22.733 22.5 22.5
M24x2 24.433 24.733 24.5 24.5
M27x2 27.433 27.733 27.5 27.5
M30x2 30.433 30.733 30.5 30.5
M33x2 33.433 33.733 33.5 33.5
M36x2 36.433 36.733 36.5 36.5
M39x2 39.433 39.733 39.5 39.5
M36x3 36.649 37.049 37 37
M39x3 39.649 40.049 40 40
Heli-Coil
thread data - metric
Pitch Diameter Nominal
Thread Size Min. 4H Max. 5H Max.
Major Diameter
Max.
METRIC COARSE
M2X0.4 2.260 2.295 2.310 2.581
M2.2x0.45 2.492 2.532 2.547 2.845
M2.5x0.45 2.792 2.832 2.847 3.145
M3x0.5 3.325 3.367 3.384 3.716
M3.5x0.6 3.890 3.940 3.959 4.354
M4x0.7 4.455 4.509 4.529 5.007
M5x0.8 5.520 5.577 5.597 6.145
M6x1 6.650 6.719 6.742 7.422
M7x1 7.650 7.719 7.742 8.422
M8x1.25 8.812 8.886 8.911 9.787
M10x1.5 10.974 11.061 11.089 12.131
M12x1.75 13.137 13.236 13.271 14.478
M14x2 15.299 15.406 15.444 16.822
M16x2 17.299 17.406 17.444 18.822
M18x2.5 19.624 19.738 19.778 21.513
M20x2.5 21.624 21.738 21.778 23.513
M22x2.5 23.624 23.738 23.778 25.513
M24x3 25.948 26.093 26.135 28.238
M27x3 28.948 29.093 29.135 31.238
M30x3.5 32.273 32.428 32.472 34.925
M33x3.5 35.273 35.428 35.472 37.925
M36x4 38.598 38.763 38.809 41.615
M39x4 41.598 41.763 41.809 44.615
METRIC FINE
M8x1 8.650 8.719 8.742 9.422
M10x1 10.650 10.719 10.742 11.422
M10x1.25 10.812 10.886 10.911 11.787
M12x1.25 12.812 12.898 12.926 13.787
M12x1.5 12.974 13.067 13.099 14.131
M14x1.5 14.974 15.067 15.099 16.131
M16x1.5 16.974 17.067 17.099 18.131
M18x1.5 18.974 19.067 19.099 20.131
M20x1.5 20.974 21.067 21.099 22.131
M22x1.5 22.974 23.067 23.099 24.131
M18x2 19.299 19.406 19.444 20.822
M20x2 21.299 21.406 21.444 22.822
M22x2 23.299 23.406 23.444 24.822
M24x2 25.299 25.414 25.454 26.822
M27x2 28.299 28.414 28.454 29.822
M30x2 31.299 31.414 31.454 32.822
M33x2 34.299 34.414 34.454 35.822
M36x2 37.299 37.414 37.454 38.822
M39x2 40.299 40.414 40.454 41.822
M36x3 37.948 38.093 38.135 40.238
M39x3 40.948 41.093 41.135 43.238
