TAP SIZE CHART

The tap size chart provides a list of standard size taps, specifying the diameter and thread spacing, for fractional, metric, and screw sizes.

The decimal equivalents of the diameters are shown in both English and Metric units. Fractional sizes are listed in inches, while metric sizes are listed in millimeters following the letter "M".

A screw size number corresponds to a diameter which is larger for a higher screw size.

The thread spacing, which may be coarse or fine, is listed after the diameter. In the fractional and screw size systems, the thread count is used, measured in threads per inch.

The metric system uses the thread pitch, which is the distance between threads, measured in millimeters. For each thread count, the equivalent thread pitch is provided and for metric taps, the approximate thread count is shown based on the pitch.

Lastly, the recommended tap drill size is provided for each standard tap size. This size drill bit should be used for drilling the initial hole that will then be tapped.

STANDARD FRactionAL
THREADS 
Tap size Diameter (in)Diameter (mm)Thread count (TPI)Thread pitch (mm)Tap drill size
#0000-1600.02100.53341600.1591/64 in
#000-1200.03400.86361200.212 #71
M1x0.20.03941.0000~1270.2000.8 mm
M1x0.250.03941.0000~1020.2500.75 mm
M1.1x0.250.04331.1000~1020.2500.85 mm
M1.1x0.20.04331.1000~1270.2000.9 mm
#00-900.04701.1938900.282 #65
M1.2x0.2 0.04721.2000~127 0.2001 mm
M1.2x0.250.04721.2000~1020.2500.95 mm
M1.4x0.20.05511.4000~1270.2001.2 mm
M1.4x0.30.05511.4000~850.3001.1 mm
#0-800.06001.5240800.3183/64 in
M1.6x0.20.06301.6000~1270.2001.4 mm
M1.6x0.350.06301.6000~730.3501.25 mm
M1.8x0.20.07091.8000~1270.2001.6 mm
M1.8x0.350.07091.8000~730.3501.45 mm
#1-640.07301.8542640.397#52
#1-720.07301.8542720.353 #53
M2x0.25 0.07872.0000~1020.2501.75 mm
M2x0.40.07872.0000~640.4001.6 mm
#2-560.08602.1844560.454 #50
#2-640.08602.1844640.397#50
M2.2x0.250.08662.2000~1020.2501.95 mm
M2.2x0.450.08662.2000~570.4501.75 mm
M2.5x0.350.09842.5000~730.3502.1 mm
M2.5x0.450.09842.5000~570.4502.05 mm
#3-480.09902.5146480.529#47
#3-560.09902.5146560.454#45
#4-400.11202.8448400.635 #43
#4-480.11202.8448480.529#42
M3x0.350.11813.0000~730.3502.6 mm
M3x0.50.11813.0000~510.500 2.5 mm
#5-40 0.12503.1750400.635#39
#5-440.12503.1750440.577#37
M3.5x0.350.13783.5000~730.350 3.1 mm
M3.5x0.6 0.13783.5000~430.6002.9 mm
#6-320.13803.5052320.794#36
#6-400.13803.5052400.635 #33
M4x0.35 0.15754.0000~730.3503.6 mm
M4x0.50.15754.0000~510.5003.5 mm
M4x0.70.15754.0000~370.700 3.3 mm
#8-32 0.16404.1656320.794#29
#8-360.16404.1656360.706#29
M4.5x0.50.17724.5000~510.500 4 mm
M4.5x0.75 0.17724.5000~340.7503.8 mm
#10-320.19004.8260320.794#21
#10-240.19004.8260241.058 #25
M5x0.50.19695.0000~510.5004.5 mm
M5x0.80.19695.0000~320.8004.2 mm
#12-240.21605.4864241.058 #17
#12-280.21605.4864280.907#15
M5.5x0.50.21655.5000~510.5005 mm
M6x0.50.23626.0000~510.500 5.5 mm
M6x0.75 0.23626.0000~340.7505.2 mm
M6x10.23626.0000~261.0005 mm
1/4-200.25006.3500201.270 #7
1/4-280.25006.3500280.907#3
M7x0.750.27567.0000~340.7506.2 mm
M7x10.27567.0000~261.000 6 mm
5/16-18 0.31257.9375181.411F
5/16-240.31257.9375241.058I
M8x0.50.31508.0000~510.500 7.5 mm
M8x0.75 0.31508.0000~340.7507.2 mm
M8x10.31508.0000~261.0007 mm
M8x1.250.31508.0000~211.250 6.8 mm
M9x0.75 0.35439.0000~340.7508.2 mm
M9x10.35439.0000~261.0008 mm
M9x1.250.35439.0000~211.250 7.8 mm
3/8-24 0.37509.5250241.058Q
3/8-160.37509.5250161.5885/16 in
M10x0.750.393710.0000~340.7509.2 mm
M10x1.50.393710.0000~171.5008.5 mm
M10x1.250.393710.0000~211.2508.8 mm
M10x10.393710.0000~261.0009 mm
M11x0.750.433111.0000~340.75010.2 mm
M11x10.433111.0000~261.000 10 mm
M11x1.5 0.433111.0000~171.5009.5 mm
7/16-140.437511.1125141.814U
7/16-200.437511.1125201.270 25/64 in
M12x1.50.472412.0000~17 1.50010.5 mm
M12x1.750.472412.0000~151.75010.2 mm
M12x0.750.472412.0000~340.75011.25 mm
M12x10.472412.0000~261.00011 mm
M12x1.250.472412.0000~211.25010.8 mm
1/2-200.500012.7000201.27029/64 in
1/2-130.500012.7000131.95427/64 in
M14x1.50.551214.0000~171.500 12.5 mm
M14x1.250.551214.0000~21 1.25012.8 mm
M14x10.551214.0000~261.00013 mm
M14x20.551214.0000~132.000 12 mm
9/16-18 0.562514.2875181.41133/64 in
9/16-120.562514.2875122.11731/64 in
M15x10.590615.0000~261.000 14 mm
M15x1.5 0.590615.0000~171.50013.5 mm
5/8-180.625015.8750181.41137/64 in
5/8-110.625015.8750112.309 17/32 in
M16x2 0.629916.0000~132.00014 mm
M16x1.50.629916.0000~171.50014.5 mm
M16x10.629916.0000~261.000 15 mm
M17x1 0.669317.0000~261.00016 mm
M17x1.50.669317.0000~171.50015.5 mm
M18x2.50.708718.0000~112.500 15.5 mm
M18x1 0.708718.0000~261.00017 mm
M18x1.50.708718.0000~171.50016.5 mm
M18x20.708718.0000~132.000 16 mm
3/4-16 0.750019.0500161.58811/16 in
3/4-100.750019.0500102.54021/32 in
M20x20.787420.0000~132.000 18 mm
M20x1.5 0.787420.0000~171.50018.5 mm
M20x10.787420.0000~261.00019 mm
M20x2.50.787420.0000~112.500 17.5 mm
M22x2 0.866122.0000~132.00020 mm
M22x1.50.866122.0000~171.50020.5 mm
M22x10.866122.0000~261.000 21 mm
M22x2.5 0.866122.0000~112.50019.5 mm
7/8-90.875022.225092.82249/64 in
7/8-140.875022.2250141.814 13/16 in
M24x3 0.944924.0000~93.00021 mm
M24x10.944924.0000~261.00023 mm
M24x1.50.944924.0000~171.500 22.5 mm
M24x2 0.944924.0000~132.00022 mm
M25x20.984325.0000~132.00023 mm
M25x10.984325.0000~261.000 24 mm
M25x1.5 0.984325.0000~171.50023.5 mm
1-141.000025.4000141.81415/16 in
1-81.000025.400083.175 7/8 in
M26x1.5 1.023626.0000~171.50024.5 mm
M27x1.51.063027.0000~171.50025.5 mm
M27x31.063027.0000~93.000 24 mm
M27x1 1.063027.0000~261.00026 mm
M27x21.063027.0000~132.00025 mm
M28x21.102428.0000~132.000 26 mm
M28x1 1.102428.0000~261.00027 mm
M28x1.51.102428.0000~171.50026.5 mm
1 1/8-121.125028.5750122.1171 3/64 in
1 1/8-71.125028.575073.62963/64 in
M30x1.51.181130.0000~171.50028.5 mm
M30x3.51.181130.0000~83.50026.5 mm
M30x21.181130.0000~132.00028 mm
1 1/4-121.250031.7500122.1171 11/64 in
1 1/4-71.250031.750073.6291 7/64 in
M33x21.299233.0000~132.00031 mm
M33x3.51.299233.0000~83.50029.5 mm
M36x31.417336.0000~93.00033 mm
M36x41.417336.0000~74.000 32 mm
1 1/2 -12 1.500038.1000122.1171 27/64 in
1 1/2-61.500038.100064.2331 11/32 in
M39x41.535439.0000~74.000 35 mm
M39x3 1.535439.0000~93.00036 mm
M42x4.51.653542.0000~64.50037.5 mm
1 3/4-121.750044.4500122.1171 43/64 in
1 3/4-51.750044.450055.0801 35/64 in
M45x4.51.771745.0000~64.50040.5 mm
M48x51.889848.0000~65.00043 mm
2-122.000050.8000122.1171 59/64 in
2-4 1/22.000050.80004.55.6441 25/32 in
M52x52.047252.0000~65.00047 mm
M56x5.52.204756.0000~55.50050.5 mm
M60x5.52.362260.0000~55.50054.5 mm
M64x62.519764.0000~56.00058 mm
M68x62.677268.0000~56.000 62 mm