Drill size chart: important tools that show standard drill sizes for different measuring systems, like fractional, metric, letter, and wire gauge number. Decimals equivalents for diameter given in metric units also English. A drill size chart helps to know the practical application of a drill size chart and related factors. So let’s get started.
Drill size chart
| Fractional (in) | Decimal (in) | Metric (mm) | Number Drill | Letter Drill | Applications |
|---|---|---|---|---|---|
| 1/64 | 0.0156 | 0.397 | #80–#79 | — | Precision electronics |
| 1/32 | 0.0313 | 0.794 | #65 | — | PCB drilling, model making |
| 3/64 | 0.0469 | 1.191 | #56 | — | Small screws |
| 1/16 | 0.0625 | 1.588 | #52 | — | Pilot holes |
| 5/64 | 0.0781 | 1.984 | #47 | — | Wood screws |
| 3/32 | 0.0938 | 2.381 | #42 | — | General drilling |
| 7/64 | 0.1094 | 2.778 | #36 | — | Machine screws |
| 1/8 | 0.1250 | 3.175 | #30 | — | Metal & wood |
| 9/64 | 0.1406 | 3.572 | #28 | — | Anchors |
| 5/32 | 0.1563 | 3.969 | #22 | — | General purpose |
| 11/64 | 0.1719 | 4.366 | #17 | — | Bolts |
| 3/16 | 0.1875 | 4.763 | #11 | — | Fabrication |
| 13/64 | 0.2031 | 5.159 | #6 | — | Structural work |
| 7/32 | 0.2188 | 5.556 | #2 | — | Fasteners |
| 15/64 | 0.2344 | 5.953 | — | A | Machine shop |
| 1/4 | 0.2500 | 6.350 | — | D | Common hardware |
| 17/64 | 0.2656 | 6.747 | — | G | Steel fabrication |
| 9/32 | 0.2813 | 7.144 | — | J | General machining |
| 19/64 | 0.2969 | 7.541 | — | L | Engineering |
| 5/16 | 0.3125 | 7.938 | — | O | Heavy-duty drilling |
| 21/64 | 0.3281 | 8.334 | — | Q | Fabrication |
| 11/32 | 0.3438 | 8.731 | — | S | Bolting |
| 23/64 | 0.3594 | 9.128 | — | U | Mechanical work |
| 3/8 | 0.3750 | 9.525 | — | W | Large fasteners |
| 25/64 | 0.3906 | 9.922 | — | Y | Industrial use |
| 13/32 | 0.4063 | 10.319 | — | Z | Machine shop |
| 7/16 | 0.4375 | 11.113 | — | — | Large holes |
| 1/2 | 0.5000 | 12.700 | — | — | Heavy fabrication |
| 9/16 | 0.5625 | 14.288 | — | — | Structural steel |
| 5/8 | 0.6250 | 15.875 | — | — | Industrial machinery |
| 3/4 | 0.7500 | 19.050 | — | — | Large fabrication |
| 7/8 | 0.8750 | 22.225 | — | — | Heavy equipment |
| 1 | 1.0000 | 25.400 | — | — | Large bore holes |
Number Drill Size Chart
Read also: Socket Size Chart
| Drill | Decimal (in) | Metric (mm) |
|---|---|---|
| #80 | 0.0135 | 0.343 |
| #70 | 0.0280 | 0.711 |
| #60 | 0.0400 | 1.016 |
| #50 | 0.0700 | 1.778 |
| #40 | 0.0980 | 2.489 |
| #30 | 0.1285 | 3.264 |
| #20 | 0.1610 | 4.089 |
| #10 | 0.1935 | 4.915 |
| #1 | 0.2280 | 5.791 |
Letter Drill Size Chart
Read :A Complete Guide to Conduit Fill Chart: Features, Importance
| Letter | Decimal (in) | Metric (mm) |
|---|---|---|
| A | 0.2340 | 5.944 |
| B | 0.2380 | 6.045 |
| C | 0.2420 | 6.147 |
| D | 0.2460 | 6.248 |
| E | 0.2500 | 6.350 |
| F | 0.2570 | 6.528 |
| G | 0.2610 | 6.629 |
| H | 0.2660 | 6.756 |
| I | 0.2720 | 6.909 |
| J | 0.2770 | 7.036 |
| K | 0.2810 | 7.137 |
| L | 0.2900 | 7.366 |
| M | 0.2950 | 7.493 |
| N | 0.3020 | 7.671 |
| O | 0.3160 | 8.026 |
| P | 0.3230 | 8.204 |
| Q | 0.3320 | 8.433 |
| R | 0.3390 | 8.611 |
| S | 0.3480 | 8.839 |
| T | 0.3580 | 9.093 |
| U | 0.3680 | 9.347 |
| V | 0.3770 | 9.576 |
| W | 0.3860 | 9.804 |
| X | 0.3970 | 10.084 |
| Y | 0.4040 | 10.262 |
| Z | 0.4130 | 10.490 |
Metric Drill Sizes
| Metric (mm) | Decimal (in) | Uses |
|---|---|---|
| 0.5 | 0.0197 | PCB micro holes |
| 1.0 | 0.0394 | Electronics |
| 1.5 | 0.0591 | Precision work |
| 2.0 | 0.0787 | Small fasteners |
| 2.5 | 0.0984 | Machine screws |
| 3.0 | 0.1181 | General engineering |
| 4.0 | 0.1575 | Fabrication |
| 5.0 | 0.1969 | Metal drilling |
| 6.0 | 0.2362 | Bolts |
| 8.0 | 0.3150 | Mechanical assemblies |
| 10.0 | 0.3937 | Structural applications |
| 12.0 | 0.4724 | Heavy fabrication |
| 16.0 | 0.6299 | Industrial work |
| 20.0 | 0.7874 | Large machinery |
| 25.0 | 0.9843 | Heavy engineering |
