thread pitch guide to help you find the correct thread pitch you need for metric fasteners. - black stainless steel coating CB10

Tap & Drill Size Info and Chart

Carbolts Tap and Drill Chart – featuring both a metric and inch table (mm and inches)

  • Scroll down if you want to see the Chart immediately. Read on if want to know a little more about the origins of taps.
  • Creating a thread requires a set of three taps corresponding to the same bit size; the bottoming, the intermediate, and the taper tap.
  • Joseph Clement popularised the tool in the mid-19th, Joseph was a British engineer and industrialist chiefly remembered as the maker of Charles Babbage's first difference engine, between 1824 and 1833.
  • Metalwork taps were popularised in the 19th century, however the first recorded use of metalworking taps goes right back to the 18th century.

Standards emerge in threading with the tap drill chart. As a consequence the development of taps corresponded to this standardisation ensuring enhanced compatibility. See the cart below.

Thread Tap, Tap and Die Metric Thread M3-M39 Drill and Tap Bits information for Tapping Various Threads

 

Tap Drill Chart (mm and inches)

TAP SIZE  CUTTING TAPS FORMING TAPS
INCH METRIC DRILL SIZE DECIMAL
EQUIVALENT		 DRILL SIZE DECIMAL
EQUIVALENT
0-80 3/64 .0469 54 .0550
M1.6 X 0.35 1.25mm .0492 1.45mm .0571
M1.8 X 0.35 1.45mm .0571 1.65mm .0650
1-64 53 .0595 51 .0650
1-72 53 .0595 51 .0650
M2 X 0.40 1.60mm .0630 1.80mm .0709
2-56 50 .0700 5/64 .0781
2-64 50 .0700 47 .0785
M2.2 X 0.45 1.75mm .0689 2.00mm .0787
M2.5 X 0.45 2.05mm .0807 2.30mm .0906
3-48 47 .0785 43 .0890
3-56 46 .0810 2.30mm .0905
4-40 43 .0890 38 .1015
4-48 42 .0935 2.60mm .1024
M3 X 0.50 2.50mm .0984 7/64 .1094
5-40 38 .1015 33 .1130
5-44 37 .1040 2.90mm .1142
M3.5 X 0.60 2.90mm .1142 3.20mm .1260
6-32 36 .1065 1/8 .1250
6-40 33 .1130 3.25mm .1280
M4 X 0.70 3.30mm .1299 3.70mm .1457
8-32 29 .1360 25 .1495
8-36 29 .1360 24 .1520
M4.5 X 0.75 3.70mm .1476 4.10mm .1614
10-24 26 .1470 11/64 .1719
10-32 21 .1590 16 .1770
M5 X 0.80 4.20mm .1654 14 .1820
12-24 16 .1770 5mm .1969
12-28 15 .1800 7 .2010
M6 X 1.00 5.00mm .1969 7/32 .2188
1/4-20 7 .2010 1 .2280
1/4-28 3 .2130 15/64 .2340
M7 X 1.00 6.00mm .2362 F .2570
5/16-18 F .2570 L .2900
5/16-24 I .2720 M .2950
M8 X 1.25 6.70mm .2638 7.40mm .2913
M8 X 1.0 7.00mm .2756 19/64 .2969
3/8-16 5/16 .3125 S .3480
3/8-24 Q .3320 T .3580
M10 X 1.50 8.50mm .3346 U .3680
M10 X 1.25 8.70mm .3425 9.40mm .3701
7/16-14 U .3680 Y .4040
7/16-20 25/64 .3906 Z .4130
M12 X 1.75 10.20mm .4016 11.20mm .4409
M12 X 1.25 10.80mm .4252 11.50mm .4528
1/2-13 27/64 .4219 15/32 .4682
1/2-20 29/64 .4531 12.25mm .4823
M14 X 2.00 12.00mm .4224 33/64 .5156
9/16-12 31/64 .4844 17/32 .5312
9/16-18 33/64 .5156 13.50mm .5315
5/8-11 17/32 .5312 14.75mm .5807
5/8-18 37/64 .5781 15.25mm .6004
M16 X 2.00 14.00mm .5512 19/32 .5938
M16 X 1.50 14.50mm .5906 15.25mm .6004
M18 X 2.50 15.50mm .6102 39/64 .6094
M18 X 1.50 16.50mm .6496 17.25mm .6791
3/4-10 21/32 0.6562 45/64 0.7031
3/4-16 11/16 0.6875 23/32 0.7188
M20 X 2.50 17.50mm 0.689
M20 X 1.50 18.50mm 0.7283
M22 X 2.50 19.50mm 0.7677
M22 X 1.50 20.50mm 0.8071
7/8-9 49/64 0.7656
7/8-14 13/16 0.8125
M24 X 3.00 21.00mm 0.8268
M24 X 2.00 22.00mm 0.8661
1-8 7/8 0.875
1-12 59/64 0.9219
M27 X 3.00 24.00mm 0.9449
M27 X 2.00 25.00mm 0.9843
1-1/8-7 63/64 0.9844
1-1/8-12 1-3/64 1.0469
M30 X 3.50 26.50mm 1.0433
M30 X 2.00 28.00mm 1.1024
1-1/4-7 1-7/64 1.1094
1-1/4-12 1-11/64 1.1719
M33 X 3.50 29.50mm 1.1614
M33 X 2.00 31.00mm 1.2205
1-3/8-6 1-7/32 1.2188
1-3/8-12 1-19/64 1.2969
M36 X 4.00 32.00mm 1.2598
M36 X 3.00 33.00mm 1.2992
1-1/2-6 1-11/32 1.3438
1-1/2-12 1-27/64 1.4219
M39 X 4.00 35.00mm 1.378
M39 X 3.00 36.00mm 1.4173