Drill size chart
Number drills run from #80 (0.0135 in, 0.34 mm) up to #1 (0.2280 in, 5.79 mm), letter drills continue from A (0.2340 in) to Z (0.4130 in), and fractional drills step by 1/64 in up to 1 in. For example, a #7 drill is 0.2010 in (5.11 mm), the tap drill for 1/4-20.
NumberLetterFractional
Drill index
Open any size for its metric equivalent, nearby sizes, the threads it can tap and the bolts it clears. Holes are drawn to scale within each series.
Number drills, #80 to #1
Fractional drills, 1/64 to 1 in
1/64"1/32"3/64"1/16"5/64"3/32"7/64"1/8"9/64"5/32"11/64"3/16"13/64"7/32"15/64"1/4"17/64"9/32"19/64"5/16"21/64"11/32"23/64"3/8"25/64"13/32"27/64"7/16"29/64"15/32"31/64"1/2"33/64"17/32"35/64"9/16"37/64"19/32"39/64"5/8"41/64"21/32"43/64"11/16"45/64"23/32"47/64"3/4"49/64"25/32"51/64"13/16"53/64"27/32"55/64"7/8"57/64"29/32"59/64"15/16"61/64"31/32"63/64"1"
How drill sizes work
Number drills
Number sizes come from the old Stubs steel wire gauge, so the size goes down as the number goes up: #1 is the largest at 0.2280 in and #80 the smallest at 0.0135 in. They fill the gaps between fractional sizes below 1/4 in, which is why so many small tap drills are number drills.
Letter drills
Letter drills pick up where number drills stop: A is just above #1 and Z is 0.4130 in. They give in-between sizes for tap drills such as F for 5/16-18 and Q for 3/8-24, and for reamer pilot holes.
Fractional and metric
Fractional drills step by 1/64 in, so the closest fraction can be up to 1/128 in away from a size you need. Metric jobber drills commonly step by 0.05 mm below 3 mm and 0.1 mm above, which makes a metric drill a close substitute for most inch sizes.
Number drills
Largest first, the way a number drill index is laid out.
| Drill | Inch | mm | Nearest metric | Tap drill for |
|---|---|---|---|---|
| #1 | 0.2280" | 5.79 | 5.8 mm | – |
| #2 | 0.2210" | 5.61 | 5.6 mm | – |
| #3 | 0.2130" | 5.41 | 5.4 mm | 1/4-28 |
| #4 | 0.2090" | 5.31 | 5.3 mm | – |
| #5 | 0.2055" | 5.22 | 5.2 mm | – |
| #6 | 0.2040" | 5.18 | 5.2 mm | – |
| #7 | 0.2010" | 5.11 | 5.1 mm | 1/4-20 |
| #8 | 0.1990" | 5.05 | 5.1 mm | – |
| #9 | 0.1960" | 4.98 | 5.0 mm | – |
| #10 | 0.1935" | 4.91 | 4.9 mm | – |
| #11 | 0.1910" | 4.85 | 4.9 mm | – |
| #12 | 0.1890" | 4.80 | 4.8 mm | – |
| #13 | 0.1850" | 4.70 | 4.7 mm | – |
| #14 | 0.1820" | 4.62 | 4.6 mm | #12-28 |
| #15 | 0.1800" | 4.57 | 4.6 mm | – |
| #16 | 0.1770" | 4.50 | 4.5 mm | #12-24 |
| #17 | 0.1730" | 4.39 | 4.4 mm | – |
| #18 | 0.1695" | 4.31 | 4.3 mm | – |
| #19 | 0.1660" | 4.22 | 4.2 mm | – |
| #20 | 0.1610" | 4.09 | 4.1 mm | – |
| #21 | 0.1590" | 4.04 | 4.0 mm | #10-32 |
| #22 | 0.1570" | 3.99 | 4.0 mm | – |
| #23 | 0.1540" | 3.91 | 3.9 mm | – |
| #24 | 0.1520" | 3.86 | 3.9 mm | – |
| #25 | 0.1495" | 3.80 | 3.8 mm | #10-24 |
| #26 | 0.1470" | 3.73 | 3.7 mm | – |
| #27 | 0.1440" | 3.66 | 3.7 mm | – |
| #28 | 0.1405" | 3.57 | 3.6 mm | – |
| #29 | 0.1360" | 3.45 | 3.5 mm | #8-32, #8-36 |
| #30 | 0.1285" | 3.26 | 3.3 mm | – |
| #31 | 0.1200" | 3.05 | 3.0 mm | – |
| #32 | 0.1160" | 2.95 | 2.95 mm | – |
| #33 | 0.1130" | 2.87 | 2.85 mm | #6-40 |
| #34 | 0.1110" | 2.82 | 2.8 mm | – |
| #35 | 0.1100" | 2.79 | 2.8 mm | – |
| #36 | 0.1065" | 2.71 | 2.7 mm | #6-32 |
| #37 | 0.1040" | 2.64 | 2.65 mm | #5-44 |
| #38 | 0.1015" | 2.58 | 2.6 mm | #5-40 |
| #39 | 0.0995" | 2.53 | 2.55 mm | – |
| #40 | 0.0980" | 2.49 | 2.5 mm | – |
| #41 | 0.0960" | 2.44 | 2.45 mm | – |
| #42 | 0.0935" | 2.37 | 2.35 mm | #4-48 |
| #43 | 0.0890" | 2.26 | 2.25 mm | #4-40 |
| #44 | 0.0860" | 2.18 | 2.2 mm | – |
| #45 | 0.0820" | 2.08 | 2.1 mm | #3-56 |
| #46 | 0.0810" | 2.06 | 2.05 mm | – |
| #47 | 0.0785" | 1.99 | 2.0 mm | #3-48 |
| #48 | 0.0760" | 1.93 | 1.95 mm | – |
| #49 | 0.0730" | 1.85 | 1.85 mm | – |
| #50 | 0.0700" | 1.78 | 1.8 mm | #2-56, #2-64 |
| #51 | 0.0670" | 1.70 | 1.7 mm | – |
| #52 | 0.0635" | 1.61 | 1.6 mm | – |
| #53 | 0.0595" | 1.51 | 1.5 mm | #1-64, #1-72 |
| #54 | 0.0550" | 1.40 | 1.4 mm | – |
| #55 | 0.0520" | 1.32 | 1.3 mm | – |
| #56 | 0.0465" | 1.18 | 1.2 mm | – |
| #57 | 0.0430" | 1.09 | 1.1 mm | – |
| #58 | 0.0420" | 1.07 | 1.05 mm | – |
| #59 | 0.0410" | 1.04 | 1.05 mm | – |
| #60 | 0.0400" | 1.02 | 1.0 mm | – |
| #61 | 0.0390" | 0.99 | 1.0 mm | – |
| #62 | 0.0380" | 0.97 | 0.95 mm | – |
| #63 | 0.0370" | 0.94 | 0.95 mm | – |
| #64 | 0.0360" | 0.91 | 0.9 mm | – |
| #65 | 0.0350" | 0.89 | 0.9 mm | – |
| #66 | 0.0330" | 0.84 | 0.85 mm | – |
| #67 | 0.0320" | 0.81 | 0.8 mm | – |
| #68 | 0.0310" | 0.79 | 0.8 mm | – |
| #69 | 0.0292" | 0.74 | 0.75 mm | – |
| #70 | 0.0280" | 0.71 | 0.7 mm | – |
| #71 | 0.0260" | 0.66 | 0.65 mm | – |
| #72 | 0.0250" | 0.64 | 0.65 mm | – |
| #73 | 0.0240" | 0.61 | 0.6 mm | – |
| #74 | 0.0225" | 0.57 | 0.55 mm | – |
| #75 | 0.0210" | 0.53 | 0.55 mm | – |
| #76 | 0.0200" | 0.51 | 0.5 mm | – |
| #77 | 0.0180" | 0.46 | 0.45 mm | – |
| #78 | 0.0160" | 0.41 | 0.4 mm | – |
| #79 | 0.0145" | 0.37 | 0.35 mm | – |
| #80 | 0.0135" | 0.34 | 0.35 mm | – |
Letter drills
| Drill | Inch | mm | Nearest metric | Tap drill for |
|---|---|---|---|---|
| Letter A | 0.2340" | 5.94 | 5.9 mm | – |
| Letter B | 0.2380" | 6.05 | 6.0 mm | – |
| Letter C | 0.2420" | 6.15 | 6.1 mm | – |
| Letter D | 0.2460" | 6.25 | 6.2 mm | – |
| Letter E | 0.2500" | 6.35 | 6.3 mm | – |
| Letter F | 0.2570" | 6.53 | 6.5 mm | 5/16-18 |
| Letter G | 0.2610" | 6.63 | 6.6 mm | – |
| Letter H | 0.2660" | 6.76 | 6.8 mm | – |
| Letter I | 0.2720" | 6.91 | 6.9 mm | 5/16-24 |
| Letter J | 0.2770" | 7.04 | 7.0 mm | – |
| Letter K | 0.2810" | 7.14 | 7.1 mm | – |
| Letter L | 0.2900" | 7.37 | 7.4 mm | – |
| Letter M | 0.2950" | 7.49 | 7.5 mm | – |
| Letter N | 0.3020" | 7.67 | 7.7 mm | – |
| Letter O | 0.3160" | 8.03 | 8.0 mm | – |
| Letter P | 0.3230" | 8.20 | 8.2 mm | – |
| Letter Q | 0.3320" | 8.43 | 8.4 mm | 3/8-24 |
| Letter R | 0.3390" | 8.61 | 8.6 mm | – |
| Letter S | 0.3480" | 8.84 | 8.8 mm | – |
| Letter T | 0.3580" | 9.09 | 9.1 mm | – |
| Letter U | 0.3680" | 9.35 | 9.3 mm | 7/16-14 |
| Letter V | 0.3770" | 9.58 | 9.6 mm | – |
| Letter W | 0.3860" | 9.80 | 9.8 mm | – |
| Letter X | 0.3970" | 10.08 | 10.1 mm | – |
| Letter Y | 0.4040" | 10.26 | 10.3 mm | – |
| Letter Z | 0.4130" | 10.49 | 10.5 mm | – |
Fractional drills
| Drill | Inch | mm | Nearest metric | Tap drill for |
|---|---|---|---|---|
| 1/64" | 0.0156" | 0.40 | 0.4 mm | – |
| 1/32" | 0.0312" | 0.79 | 0.8 mm | – |
| 3/64" | 0.0469" | 1.19 | 1.2 mm | #0-80 |
| 1/16" | 0.0625" | 1.59 | 1.6 mm | – |
| 5/64" | 0.0781" | 1.98 | 2.0 mm | – |
| 3/32" | 0.0938" | 2.38 | 2.4 mm | – |
| 7/64" | 0.1094" | 2.78 | 2.8 mm | – |
| 1/8" | 0.1250" | 3.17 | 3.2 mm | – |
| 9/64" | 0.1406" | 3.57 | 3.6 mm | – |
| 5/32" | 0.1562" | 3.97 | 4.0 mm | – |
| 11/64" | 0.1719" | 4.37 | 4.4 mm | – |
| 3/16" | 0.1875" | 4.76 | 4.8 mm | – |
| 13/64" | 0.2031" | 5.16 | 5.2 mm | – |
| 7/32" | 0.2188" | 5.56 | 5.6 mm | – |
| 15/64" | 0.2344" | 5.95 | 6.0 mm | – |
| 1/4" | 0.2500" | 6.35 | 6.3 mm | – |
| 17/64" | 0.2656" | 6.75 | 6.7 mm | – |
| 9/32" | 0.2812" | 7.14 | 7.1 mm | – |
| 19/64" | 0.2969" | 7.54 | 7.5 mm | – |
| 5/16" | 0.3125" | 7.94 | 7.9 mm | 3/8-16 |
| 21/64" | 0.3281" | 8.33 | 8.3 mm | – |
| 11/32" | 0.3438" | 8.73 | 8.7 mm | – |
| 23/64" | 0.3594" | 9.13 | 9.1 mm | – |
| 3/8" | 0.3750" | 9.52 | 9.5 mm | – |
| 25/64" | 0.3906" | 9.92 | 9.9 mm | 7/16-20 |
| 13/32" | 0.4062" | 10.32 | 10.3 mm | – |
| 27/64" | 0.4219" | 10.72 | 10.7 mm | 1/2-13 |
| 7/16" | 0.4375" | 11.11 | 11.1 mm | – |
| 29/64" | 0.4531" | 11.51 | 11.5 mm | 1/2-20 |
| 15/32" | 0.4688" | 11.91 | 11.9 mm | – |
| 31/64" | 0.4844" | 12.30 | 12.3 mm | 9/16-12 |
| 1/2" | 0.5000" | 12.70 | 12.7 mm | – |
| 33/64" | 0.5156" | 13.10 | 13.1 mm | 9/16-18 |
| 17/32" | 0.5312" | 13.49 | 13.5 mm | 5/8-11 |
| 35/64" | 0.5469" | 13.89 | 13.9 mm | – |
| 9/16" | 0.5625" | 14.29 | 14.3 mm | – |
| 37/64" | 0.5781" | 14.68 | 14.7 mm | 5/8-18 |
| 19/32" | 0.5938" | 15.08 | 15.1 mm | – |
| 39/64" | 0.6094" | 15.48 | 15.5 mm | – |
| 5/8" | 0.6250" | 15.88 | 15.9 mm | – |
| 41/64" | 0.6406" | 16.27 | 16.3 mm | – |
| 21/32" | 0.6562" | 16.67 | 16.7 mm | 3/4-10 |
| 43/64" | 0.6719" | 17.07 | 17.1 mm | – |
| 11/16" | 0.6875" | 17.46 | 17.5 mm | 3/4-16 |
| 45/64" | 0.7031" | 17.86 | 17.9 mm | – |
| 23/32" | 0.7188" | 18.26 | 18.3 mm | – |
| 47/64" | 0.7344" | 18.65 | 18.7 mm | – |
| 3/4" | 0.7500" | 19.05 | 19.0 mm | – |
| 49/64" | 0.7656" | 19.45 | 19.4 mm | 7/8-9 |
| 25/32" | 0.7812" | 19.84 | 19.8 mm | – |
| 51/64" | 0.7969" | 20.24 | 20.2 mm | – |
| 13/16" | 0.8125" | 20.64 | 20.6 mm | 7/8-14 |
| 53/64" | 0.8281" | 21.03 | 21.0 mm | – |
| 27/32" | 0.8438" | 21.43 | 21.4 mm | – |
| 55/64" | 0.8594" | 21.83 | 21.8 mm | – |
| 7/8" | 0.8750" | 22.22 | 22.2 mm | 1-8 |
| 57/64" | 0.8906" | 22.62 | 22.6 mm | – |
| 29/32" | 0.9062" | 23.02 | 23.0 mm | – |
| 59/64" | 0.9219" | 23.42 | 23.4 mm | 1-12 |
| 15/16" | 0.9375" | 23.81 | 23.8 mm | – |
| 61/64" | 0.9531" | 24.21 | 24.2 mm | – |
| 31/32" | 0.9688" | 24.61 | 24.6 mm | – |
| 63/64" | 0.9844" | 25.00 | 25.0 mm | – |
| 1" | 1.0000" | 25.40 | 25.4 mm | – |
All inch drills by size
Number, letter and fractional drills merged in one list, smallest to largest.
| Drill | Series | Inch | mm |
|---|---|---|---|
| #80 | Number | 0.0135" | 0.34 |
| #79 | Number | 0.0145" | 0.37 |
| 1/64" | Fractional | 0.0156" | 0.40 |
| #78 | Number | 0.0160" | 0.41 |
| #77 | Number | 0.0180" | 0.46 |
| #76 | Number | 0.0200" | 0.51 |
| #75 | Number | 0.0210" | 0.53 |
| #74 | Number | 0.0225" | 0.57 |
| #73 | Number | 0.0240" | 0.61 |
| #72 | Number | 0.0250" | 0.64 |
| #71 | Number | 0.0260" | 0.66 |
| #70 | Number | 0.0280" | 0.71 |
| #69 | Number | 0.0292" | 0.74 |
| #68 | Number | 0.0310" | 0.79 |
| 1/32" | Fractional | 0.0312" | 0.79 |
| #67 | Number | 0.0320" | 0.81 |
| #66 | Number | 0.0330" | 0.84 |
| #65 | Number | 0.0350" | 0.89 |
| #64 | Number | 0.0360" | 0.91 |
| #63 | Number | 0.0370" | 0.94 |
| #62 | Number | 0.0380" | 0.97 |
| #61 | Number | 0.0390" | 0.99 |
| #60 | Number | 0.0400" | 1.02 |
| #59 | Number | 0.0410" | 1.04 |
| #58 | Number | 0.0420" | 1.07 |
| #57 | Number | 0.0430" | 1.09 |
| #56 | Number | 0.0465" | 1.18 |
| 3/64" | Fractional | 0.0469" | 1.19 |
| #55 | Number | 0.0520" | 1.32 |
| #54 | Number | 0.0550" | 1.40 |
| #53 | Number | 0.0595" | 1.51 |
| 1/16" | Fractional | 0.0625" | 1.59 |
| #52 | Number | 0.0635" | 1.61 |
| #51 | Number | 0.0670" | 1.70 |
| #50 | Number | 0.0700" | 1.78 |
| #49 | Number | 0.0730" | 1.85 |
| #48 | Number | 0.0760" | 1.93 |
| 5/64" | Fractional | 0.0781" | 1.98 |
| #47 | Number | 0.0785" | 1.99 |
| #46 | Number | 0.0810" | 2.06 |
| #45 | Number | 0.0820" | 2.08 |
| #44 | Number | 0.0860" | 2.18 |
| #43 | Number | 0.0890" | 2.26 |
| #42 | Number | 0.0935" | 2.37 |
| 3/32" | Fractional | 0.0938" | 2.38 |
| #41 | Number | 0.0960" | 2.44 |
| #40 | Number | 0.0980" | 2.49 |
| #39 | Number | 0.0995" | 2.53 |
| #38 | Number | 0.1015" | 2.58 |
| #37 | Number | 0.1040" | 2.64 |
| #36 | Number | 0.1065" | 2.71 |
| 7/64" | Fractional | 0.1094" | 2.78 |
| #35 | Number | 0.1100" | 2.79 |
| #34 | Number | 0.1110" | 2.82 |
| #33 | Number | 0.1130" | 2.87 |
| #32 | Number | 0.1160" | 2.95 |
| #31 | Number | 0.1200" | 3.05 |
| 1/8" | Fractional | 0.1250" | 3.17 |
| #30 | Number | 0.1285" | 3.26 |
| #29 | Number | 0.1360" | 3.45 |
| #28 | Number | 0.1405" | 3.57 |
| 9/64" | Fractional | 0.1406" | 3.57 |
| #27 | Number | 0.1440" | 3.66 |
| #26 | Number | 0.1470" | 3.73 |
| #25 | Number | 0.1495" | 3.80 |
| #24 | Number | 0.1520" | 3.86 |
| #23 | Number | 0.1540" | 3.91 |
| 5/32" | Fractional | 0.1562" | 3.97 |
| #22 | Number | 0.1570" | 3.99 |
| #21 | Number | 0.1590" | 4.04 |
| #20 | Number | 0.1610" | 4.09 |
| #19 | Number | 0.1660" | 4.22 |
| #18 | Number | 0.1695" | 4.31 |
| 11/64" | Fractional | 0.1719" | 4.37 |
| #17 | Number | 0.1730" | 4.39 |
| #16 | Number | 0.1770" | 4.50 |
| #15 | Number | 0.1800" | 4.57 |
| #14 | Number | 0.1820" | 4.62 |
| #13 | Number | 0.1850" | 4.70 |
| 3/16" | Fractional | 0.1875" | 4.76 |
| #12 | Number | 0.1890" | 4.80 |
| #11 | Number | 0.1910" | 4.85 |
| #10 | Number | 0.1935" | 4.91 |
| #9 | Number | 0.1960" | 4.98 |
| #8 | Number | 0.1990" | 5.05 |
| #7 | Number | 0.2010" | 5.11 |
| 13/64" | Fractional | 0.2031" | 5.16 |
| #6 | Number | 0.2040" | 5.18 |
| #5 | Number | 0.2055" | 5.22 |
| #4 | Number | 0.2090" | 5.31 |
| #3 | Number | 0.2130" | 5.41 |
| 7/32" | Fractional | 0.2188" | 5.56 |
| #2 | Number | 0.2210" | 5.61 |
| #1 | Number | 0.2280" | 5.79 |
| Letter A | Letter | 0.2340" | 5.94 |
| 15/64" | Fractional | 0.2344" | 5.95 |
| Letter B | Letter | 0.2380" | 6.05 |
| Letter C | Letter | 0.2420" | 6.15 |
| Letter D | Letter | 0.2460" | 6.25 |
| 1/4" | Fractional | 0.2500" | 6.35 |
| Letter E | Letter | 0.2500" | 6.35 |
| Letter F | Letter | 0.2570" | 6.53 |
| Letter G | Letter | 0.2610" | 6.63 |
| 17/64" | Fractional | 0.2656" | 6.75 |
| Letter H | Letter | 0.2660" | 6.76 |
| Letter I | Letter | 0.2720" | 6.91 |
| Letter J | Letter | 0.2770" | 7.04 |
| Letter K | Letter | 0.2810" | 7.14 |
| 9/32" | Fractional | 0.2812" | 7.14 |
| Letter L | Letter | 0.2900" | 7.37 |
| Letter M | Letter | 0.2950" | 7.49 |
| 19/64" | Fractional | 0.2969" | 7.54 |
| Letter N | Letter | 0.3020" | 7.67 |
| 5/16" | Fractional | 0.3125" | 7.94 |
| Letter O | Letter | 0.3160" | 8.03 |
| Letter P | Letter | 0.3230" | 8.20 |
| 21/64" | Fractional | 0.3281" | 8.33 |
| Letter Q | Letter | 0.3320" | 8.43 |
| Letter R | Letter | 0.3390" | 8.61 |
| 11/32" | Fractional | 0.3438" | 8.73 |
| Letter S | Letter | 0.3480" | 8.84 |
| Letter T | Letter | 0.3580" | 9.09 |
| 23/64" | Fractional | 0.3594" | 9.13 |
| Letter U | Letter | 0.3680" | 9.35 |
| 3/8" | Fractional | 0.3750" | 9.52 |
| Letter V | Letter | 0.3770" | 9.58 |
| Letter W | Letter | 0.3860" | 9.80 |
| 25/64" | Fractional | 0.3906" | 9.92 |
| Letter X | Letter | 0.3970" | 10.08 |
| Letter Y | Letter | 0.4040" | 10.26 |
| 13/32" | Fractional | 0.4062" | 10.32 |
| Letter Z | Letter | 0.4130" | 10.49 |
| 27/64" | Fractional | 0.4219" | 10.72 |
| 7/16" | Fractional | 0.4375" | 11.11 |
| 29/64" | Fractional | 0.4531" | 11.51 |
| 15/32" | Fractional | 0.4688" | 11.91 |
| 31/64" | Fractional | 0.4844" | 12.30 |
| 1/2" | Fractional | 0.5000" | 12.70 |
| 33/64" | Fractional | 0.5156" | 13.10 |
| 17/32" | Fractional | 0.5312" | 13.49 |
| 35/64" | Fractional | 0.5469" | 13.89 |
| 9/16" | Fractional | 0.5625" | 14.29 |
| 37/64" | Fractional | 0.5781" | 14.68 |
| 19/32" | Fractional | 0.5938" | 15.08 |
| 39/64" | Fractional | 0.6094" | 15.48 |
| 5/8" | Fractional | 0.6250" | 15.88 |
| 41/64" | Fractional | 0.6406" | 16.27 |
| 21/32" | Fractional | 0.6562" | 16.67 |
| 43/64" | Fractional | 0.6719" | 17.07 |
| 11/16" | Fractional | 0.6875" | 17.46 |
| 45/64" | Fractional | 0.7031" | 17.86 |
| 23/32" | Fractional | 0.7188" | 18.26 |
| 47/64" | Fractional | 0.7344" | 18.65 |
| 3/4" | Fractional | 0.7500" | 19.05 |
| 49/64" | Fractional | 0.7656" | 19.45 |
| 25/32" | Fractional | 0.7812" | 19.84 |
| 51/64" | Fractional | 0.7969" | 20.24 |
| 13/16" | Fractional | 0.8125" | 20.64 |
| 53/64" | Fractional | 0.8281" | 21.03 |
| 27/32" | Fractional | 0.8438" | 21.43 |
| 55/64" | Fractional | 0.8594" | 21.83 |
| 7/8" | Fractional | 0.8750" | 22.22 |
| 57/64" | Fractional | 0.8906" | 22.62 |
| 29/32" | Fractional | 0.9062" | 23.02 |
| 59/64" | Fractional | 0.9219" | 23.42 |
| 15/16" | Fractional | 0.9375" | 23.81 |
| 61/64" | Fractional | 0.9531" | 24.21 |
| 31/32" | Fractional | 0.9688" | 24.61 |
| 63/64" | Fractional | 0.9844" | 25.00 |
| 1" | Fractional | 1.0000" | 25.40 |
Metric drill to nearest inch drill
For each metric size from 0.5 to 13 mm, the closest number, letter or fractional drill. Difference is inch drill minus metric size.
| Metric | In inches | Nearest inch drill | Its size | Difference |
|---|---|---|---|---|
| 0.5 mm | 0.0197" | #76 | 0.0200" | +0.0003" |
| 1.0 mm | 0.0394" | #61 | 0.0390" | −0.0004" |
| 1.5 mm | 0.0591" | #53 | 0.0595" | +0.0004" |
| 2.0 mm | 0.0787" | #47 | 0.0785" | −0.0002" |
| 2.5 mm | 0.0984" | #40 | 0.0980" | −0.0004" |
| 3.0 mm | 0.1181" | #31 | 0.1200" | +0.0019" |
| 3.5 mm | 0.1378" | #29 | 0.1360" | −0.0018" |
| 4.0 mm | 0.1575" | #22 | 0.1570" | −0.0005" |
| 4.5 mm | 0.1772" | #16 | 0.1770" | −0.0002" |
| 5.0 mm | 0.1969" | #9 | 0.1960" | −0.0009" |
| 5.5 mm | 0.2165" | 7/32" | 0.2188" | +0.0022" |
| 6.0 mm | 0.2362" | Letter B | 0.2380" | +0.0018" |
| 6.5 mm | 0.2559" | Letter F | 0.2570" | +0.0011" |
| 7.0 mm | 0.2756" | Letter J | 0.2770" | +0.0014" |
| 7.5 mm | 0.2953" | Letter M | 0.2950" | −0.0003" |
| 8.0 mm | 0.3150" | Letter O | 0.3160" | +0.0010" |
| 8.5 mm | 0.3346" | Letter Q | 0.3320" | −0.0026" |
| 9.0 mm | 0.3543" | Letter T | 0.3580" | +0.0037" |
| 9.5 mm | 0.3740" | 3/8" | 0.3750" | +0.0010" |
| 10.0 mm | 0.3937" | 25/64" | 0.3906" | −0.0031" |
| 10.5 mm | 0.4134" | Letter Z | 0.4130" | −0.0004" |
| 11.0 mm | 0.4331" | 7/16" | 0.4375" | +0.0044" |
| 11.5 mm | 0.4528" | 29/64" | 0.4531" | +0.0004" |
| 12.0 mm | 0.4724" | 15/32" | 0.4688" | −0.0037" |
| 12.5 mm | 0.4921" | 31/64" | 0.4844" | −0.0078" |
| 13.0 mm | 0.5118" | 33/64" | 0.5156" | +0.0038" |