Tag: UNC

Tap Drill Size – UNC


INCH SIZES – NATIONAL COARSE
TAP SIZE DRILL SIZE
#0-80 3/64″
#1-64 #53
#2-56 #51
#3-48 5/64″
#4-40 #43
#5-40 #39
#6-32 #36
#8-32 #29
#10-24 #25
#12-24 #17
1/4-20 #7
5/16-18 F
3/8-16 5/16
7/16-14 U
1/2-13 27/64
9/16-12 31/64
5/8-11 17/32
3/4-10 21/32
7/8-9 49/64
1″-8 7/8
1-1/8-7 63/64
1-1/4-7 1-7/64
1-1/2-6 1-11/32
1-3/4-5 1-35/64
2″-4-1/2 1-25/32
 
Metric Tap Drill Sizes
Standard UNF Tap Drill Sizes
Standard NPT Tap Drill Sizes

Unified Screw Threads – Course (UNC)


Size Major Dia Threads Per Inch Pitch Dia Minor Dia External Minor Dia Internal Minor Dia Area Tensile Stress Area
# inch tpi inch inch inch sq. inch sq. inch
#1 0.073 64 0.0629 0.0544 0.0561 0.00218 0.00263
#2 0.086 56 0.0744 0.0648 0.0667 0.0031 0.0037
#3 0.099 48 0.0855 0.0741 0.0764 0.00406 0.00487
#4 0.112 40 0.0958 0.0822 0.0849 0.00496 0.00604
#5 0.125 40 0.1088 0.0952 0.0979 0.00672 0.00796
#6 0.138 32 0.1177 0.1008 0.1042 0.00745 0.00909
#8 0.164 32 0.1437 0.1268 0.1302 0.01196 0.014
#10 0.19 24 0.1629 0.1404 0.1449 0.0145 0.0175
#12 0.216 24 0.1889 0.1664 0.1709 0.0206 0.0242
¼ 0.25 20 0.2175 0.1905 0.1959 0.0269 0.0318
5/16 0.3125 18 0.2764 0.2464 0.2524 0.0454 0.0524
3/8 0.375 16 0.3344 0.3005 0.3073 0.0678 0.0775
7/16 0.4375 14 0.3911 0.3525 0.3602 0.0933 0.1063
½ 0.5 13 0.45 0.4084 0.4167 0.1257 0.1419
9/16 0.5625 12 0.5084 0.4633 0.4723 0.162 0.182
5/8 0.625 11 0.566 0.5168 0.5266 0.202 0.226
¾ 0.75 10 0.685 0.6309 0.6417 0.302 0.334
7/8 0.875 9 0.8028 0.7427 0.7547 0.419 0.462
1 1 8 0.9188 0.8512 0.8647 0.551 0.606
1-1/8 1.125 7 1.0322 0.9549 0.9704 0.693 0.763
1¼ 1.25 7 1.1572 1.0799 1.0954 0.89 0.969
1-3/8 1.375 6 1.2667 1.1766 1.1946 1.054 1.155
1½ 1.5 6 1.3917 1.3016 1.3196 1.294 1.405
1¾ 1.75 5 1.6201 1.5119 1.5335 1.74 1.9
2 2 4.5 1.8557 1.7353 1.7594 2.3 2.5
2¼ 2.25 4.5 2.1057 1.9853 2.0094 3.02 3.25
2½ 2.5 4 2.3376 2.2023 2.2294 3.72 4
2¾ 2.75 4 2.5876 2.4523 2.4794 4.62 4.93
3 3 4 2.8376 2.7023 2.7294 5.62 5.97
3¼ 3.25 4 3.0876 2.9523 2.9794 6.72 7.1
3½ 3.5 4 3.3376 3.2023 3.2294 7.92 8.33
3¾ 3.75 4 3.5876 3.4523 3.4794 9.21 9.66
4 4 4 3.8376 3.7023 3.7294 10.61 11.08