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UNIFIED COARSE

Nominal Thread Size Suggested Drill Size “F” MINIMUM DRILLING DEPTH FOR EACH INSERT LENGTH
Plug Taps Bottoming Taps
Aluminum Steel, Magnesium, Plastic
Drill Size Drill in Drill Size Drill In 1 Dia. 1-1/2 Dia. 2 Dia. 2-1/2 Dia. 3 Dia. 1 Dia. 1-1/2 Dia. 2 Dia. 2-1/2 Dia. 3 Dia.
1 -64 #47 0.0785 #46 0.0810 0.203 0.24 0.276 0.313 0.349 0.136 0.172 0.209 0.245 0.282
2 -56 3/32 0.0938 #41 0.0960 0.236 0.279 0.322 0.365 0.408 0.157 0.2 0.243 0.286 0.329
3-48 #36 0.1065 7/64 0.1094 0.273 0.323 0.372 0.422 0.471 0.182 0.232 0.281 0.331 0.38
4 -40 #31 0.1200 #31 0.1200 0.318 0.374 0.43 0.486 0.542 0.212 0.268 0.324 0.38 0.436
5 -40 3.4mm 0.1339 #29 0.1360 0.338 0.4 0.462 0.525 0.588 0.225 0.288 0.35 0.412 0.475
6-32 #26 0.1470 #25 0.1495 0.394 0.464 0.532 0.602 0.67 0.263 0.332 0.401 0.47 0.539
8 -32 #17 0.1730 #16 0.1770 0.434 0.516 0.598 0.68 0.762 0.289 0.371 0.453 0.535 0.617
10 -24 13/64 0.2031 #5 0.2055 0.535 0.63 0.725 0.82 0.915 0.357 0.452 0.547 0.642 0.737
12 -24 #1 0.2280 #1 0.2280 0.574 0.682 0.79 0.898 1.006 0.383 0.491 0.599 0.707 0.815
1/4 -20 H 0.2660 H 0.2660 0.675 0.8 0.925 1.05 1.175 0.45 0.575 0.7 0.825 0.95
5/16-18 Q 0.3320 Q 0.3320 0.801 0.957 1.113 1.269 1.425 0.534 0.69 0.846 1.002 1.158
3/8 -16 X 0.3970 X 0.3970 0.75 0.938 1.125 1.312 1.5 0.625 0.812 1 1.188 1.375
7/16 -14 29/64 0.4531 29/64 0.4531 0.867 1.086 1.305 1.524 1.743 0.724 0.943 1.162 1.381 1.6
1/2 -13 33/64 0.5156 17/32 0.5312 0.962 1.212 1.462 1.712 1.962 0.808 1.058 1.308 1.558 1.808
9/16 -12 37/64 0.5781 19/32 0.5938 1.062 1.343 1.624 1.905 2.186 0.895 1.176 1.457 1.738 2.019
5/8-11 21/32 0.6562 21/32 0.6562 1.17 1.483 1.795 2.108 2.42 0.989 1.301 1.614 1.926 2.239
3/4 -10 25/32 0.7812 25/32 0.7812 1.35 1.725 2.1 2.475 2.85 1.15 1.525 1.9 2.275 2.65
7/8 -9 29/32 0.9062 29/32 0.9062 1.542 1.979 2.417 2.854 3.292 1.319 1.757 2.194 2.632 3.069
1 -8 1-1/32 1.0312 1-1/32 1.0312 1.75 2.25 2.75 3.25 3.75 1.5 2 2.5 3 3.5
1-1/8-7 1-11/64 1.1719 1-11/64 1.1719 1.982 2.545 3.107 3.67 4.232 1.696 2.259 2.821 3.384 3.946
1-1/4   - 7 1-19/64 1.2969 1-19/64 1.2969 2.107 2.732 3.357 3.982 4.607 1.821 2.446 3.071 3.696 4.321
1-3/8 -6 1-27/64 1.4219 1-27/64 1.4219 2.375 3.062 3.75 4.437 5.125 2.042 2.729 3.417 4.104 4.792
1-1/2-6 1-35/64 1.5469 1-35/64 1.5469 2.5 3.25 4 4.75 5.5 2.167 2.917 3.667 4.417 5.167

UNIFIED FINE

Nominal Thread Size Suggested Drill Size “F” MINIMUM DRILLING DEPTH FOR EACH INSERT LENGTH
Plug Taps Bottoming Taps
Aluminum Steel, Magnesium, Plastic
Drill Size Drill in Drill Size Drill In 1 Dia. 1-1/2 Dia. 2 Dia. 2-1/2 Dia. 3 Dia. 1 Dia. 1-1/2 Dia. 2 Dia. 2-1/2 Dia. 3 Dia.
2-64 2.35mm 0.0925 2.35mm 0.0925 0.223 0.266 0.309 0.352 0.395 0.149 0.192 0.235 0.278 0.321
3 -56 #37 0.104 #36 0.1065 0.256 0.305 0.355 0.404 0.454 0.17 0.22 0.269 0.319 0.368
4 -48 3mm 0.1181 #31 0.1200 0.293 0.349 0.405 0.461 0.517 0.195 0.251 0.307 0.363 0.419
6-40 #26 0.147 #25 0.1495 0.357 0.426 0.495 0.564 0.633 0.238 0.307 0.376 0.445 0.514
8 -36 #17 0.173 #16 0.1770 0.413 0.495 0.577 0.659 0.741 0.275 0.357 0.439 0.521 0.603
10 -32 #7 0.201 13/64 0.2031 0.472 0.568 0.662 0.758 0.852 0.315 0.41 0.505 0.6 0.695
1/4 -28 G 0.261 6.7mm 0.2638 0.589 0.714 0.839 0.964 1.089 0.393 0.518 0.643 0.768 0.893
5/16 -24 21/64 0.3281 21/64 0.3281 0.718 0.874 1.03 1.186 1.342 0.479 0.635 0.791 0.947 1.103
3/8 -24 25/64 0.3906 25/64 0.3906 0.625 0.812 1 1.187 1.375 0.542 0.729 0.917 1.104 1.292
7/16 -20 29/64 0.4531 29/64 0.4531 0.738 0.957 1.176 1.395 1.614 0.638 0.857 1.076 1.295 1.514
1/2-20 33/64 0.5156 33/64 0.5156 0.8 1.05 1.3 1.55 1.8 0.7 0.95 1.2 1.45 1.7
9/16-18 37/64 0.5781 37/64 0.5781 0.895 1.176 1.457 1.738 2.019 0.784 1.065 1.346 1.627 1.908
5/8-18 41/64 0.6406 41/64 0.6406 0.958 1.271 1.583 1.896 2.208 0.847 1.16 1.472 1.785 2.097
3/4-16 49/64 0.7656 49/64 0.7656 1.125 1.5 1.875 2.25 2.625 1 1.375 1.75 2.125 2.5
7/8-14 57/64 0.8906 57/64 0.8906 1.304 1.741 2.179 2.616 3.054 1.161 1.598 2.036 2.473 2.911
1-14 1-1/64 1.0156 1-1/32 1.0312 1.429 1.929 2.429 2.929 3.429 1.286 1.786 2.286 2.786 3.286
1 -12 1-1/64 1.0156 1-1/32 1.0312 1.5 2 2.5 3 3.5 1.333 1.833 2.333 2.833 3.333
1-1/8-12 1-9/64 1.1406 1-5/32 1.1562 1.625 2.187 2.75 3.312 3.875 1.458 2.021 2.583 3.146 3.708
1-1/4 -12 1-17/64 1.2656 1-9/32 1.2812 1.75 2.375 3 3.625 4.25 1.583 2.208 2.833 3.458 4.083
1-3/8 -12 1-25/64 1.3906 1-13/32 1.4062 1.875 2.562 3.25 3.937 4.625 1.708 2.396 3.083 3.771 4.458
1-1/2 -12 1-33/64 1.5156 1-17/32 1.5312 2 2.75 3.5 4.25 5 1.833 2.583 3.333 4.083 4.833

METRIC COARSE

Nominal Thread Size Suggested Drill Size   “F” MINIMUM DRILLING DEPTH FOR EACH INSERT LENGTH
Aluminum Steel, Magnesium, Plastic Plug Taps Bottoming Taps
Drill Size Drill In Drill Size Drill In 1 Dia. 1-1/2 Dia. 2 Dia. 2-1/2 Dia. 3 Dia. 1 Dia. 1-1/2 Dia. 2 Dia. 2-1/2 Dia. 3 Dia.
M2X0.4 2.1 0.0827 2.1 0.0827 5.4 6.4 7.4 8.4 9.4 3.6 4.6 5.6 6.6 7.6
M2.2x0.45 2.3 0.0906 2.35 0.0925 6 7.1 8.2 9.3 10.4 4 5.1 6.2 7.3 8.4
M2.5x0.45 2.55 0.1004 2.65 0.1043 6.45 7.7 8.95 10.2 11.45 4.3 5.55 6.8 8.05 9.3
M3x0.5 3.15 0.1240 3.2 0.1260 7.5 9 10.5 12 13.5 5 6.5 8 9.5 11
M3.5x0.6 3.7 0.1457 3.7 0.1457 8.85 10.6 12.35 14.1 15.85 5.9 7.65 9.4 11.15 12.9
M4x0.7 4.2 0.1654 4.25 0.1673 10.2 12.2 14.2 16.2 18.2 6.8 8.8 10.8 12.8 14.8
M5x0.8 5.2 0.2047 5.3 0.2087 12.3 14.8 17.3 19.8 22.3 8.2 10.7 13.2 15.7 18.2
M6x1 6.25 0.2461 6.3 0.2480 15 18 21 24 27 10 13 16 19 22
M7x1 7.25 0.2854 7.3 0.2874 16.5 20 23.5 27 30.5 11 14.5 18 21.5 25
M8x1.25 8.3 0.3268 8.4 0.3307 19.5 23.5 27.5 31.5 35.5 13 17 21 25 29
M10x1.5 10.5 0.4134 10.5 0.4134 19 24 29 34 39 16 21 26 31 36
M12x1.75 12.5 0.4921 12.5 0.4921 22.5 28.5 34.5 40.5 46.5 19 25 31 37 43
M14x2 14.5 0.5709 14.5 0.5709 26 33 40 47 54 22 29 36 43 50
M16x2 16.5 0.6496 16.5 0.6496 28 36 44 52 60 24 32 40 48 56
M18x2.5 18.75 0.7382 18.75 0.7382 33 42 51 60 69 28 37 46 55 64
M20x2.5 20.75 0.8169 20.75 0.8169 35 45 55 65 75 30 40 50 60 70
M22x2.5 22.75 0.8957 22.75 0.8957 37 48 59 70 81 32 43 54 65 76
M24x3 24.75 0.9744 24.75 0.9744 42 54 66 78 90 36 48 60 72 84
M27x3 27.75 1.0925 27.75 1.0925 45 58.5 72 85.5 99 39 52.5 66 79.5 93
M30x3.5 31 1.2205 31 1.2205 51 66 81 96 111 44 59 74 89 104
M33x3.5 34 1.3386 34 1.3386 54 70.5 87 103.5 120 47 63.5 80 96.5 113
M36x4 37 1.4567 37 1.4567 60 78 96 114 132 52 70 88 106 124
M39x4 40 1.5748 40 1.5748 63 82.5 102 121.5 141 55 74.5 94 113.5 133

METRIC FINE

Nominal Thread Size Suggested Drill Size “F” MINIMUM DRILLING DEPTH FOR EACH INSERT LENGTH
Aluminum Steel, Magnesium, Plastic Plug Taps Bottoming Taps
Drill Size Drill In Drill Size Drill In 1 Dia. 1-1/2 Dia. 2 Dia. 2-1/2 Dia. 3 Dia. 1 Dia. 1-1/2 Dia. 2 Dia. 2-1/2 Dia. 3 Dia.
M8x1 8.25 0.3248 8.3 0.3268 18 22 26 30 34 12 16 20 24 28
M10x1 10.25 0.4035 10.25 0.4035 16 21 26 31 36 14 19 24 29 34
M10x1.25 10.25 0.4035 10.25 0.4035 17.5 22.5 27.5 32.5 37.5 15 20 25 30 35
M12x1.25 12.25 0.4823 12.25 0.4823 19.5 25.5 31.5 37.5 43.5 17 23 29 35 41
M12x1.5 12.25 0.4823 12.5 0.4921 21 27 33 39 45 18 24 30 36 42
M14x1.5 14.25 0.5610 14.5 0.5709 23 30 37 44 51 20 27 34 41 48
M16x1.5 16.25 0.6398 16.5 0.6496 25 33 41 49 57 22 30 38 46 54
M18x1.5 18.25 0.7185 18.5 0.7283 27 36 45 54 63 24 33 42 51 60
M20x1.5 20.25 0.7972 20.5 0.8071 29 39 49 59 69 26 36 46 56 66
M22x1.5 22.25 0.8760 22.5 0.8858 31 42 53 64 75 28 39 50 61 72
M18x2 18.5 0.7283 18.5 0.7283 30 39 48 57 66 26 35 44 53 62
M20x2 20.5 0.8071 20.5 0.8071 32 42 52 62 72 28 38 48 58 68
M22x2 22.5 0.8858 22.5 0.8858 34 45 56 67 78 30 41 52 63 74
M24x2 24.5 0.9646 24.5 0.9646 36 48 60 72 84 32 44 56 68 80
M27x2 27.5 1.0827 27.5 1.0827 39 52.5 66 79.5 93 35 48.5 62 75.5 89
M30x2 30.5 1.2008 30.5 1.2008 42 57 72 87 102 38 53 68 83 98
M33x2 33.5 1.3189 33.5 1.3189 45 61.5 78 94.5 111 41 57.5 74 90.5 107
M36x2 36.5 1.4370 36.5 1.4370 48 66 84 102 120 44 62 80 98 116
M39x2 39.5 1.5551 39.5 1.5551 51 70.5 90 109 129 47 66.5 86 105.5 125
M36x3 37 1.4567 37 1.4567 54 72 90 108 126 48 66 84 102 120
M39x3 40 1.5748 40 1.5748 57 76.5 96 115.5 135 51 70.5 90 109.5 129

 

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