Tap and Drill Bit Sizes: A Reference Guide from Drill America
Presented by Drill America and Zoro Staff
Whether you're running a business or simply choosing the right gear for an upcoming job, this guide from Drill America and Zoro will help you quickly and easily find the correct drill bit size for tapping with clean, accurate threads and consistent results. In the guide below, you'll find easy-to-read charts for both NC-NF (National Coarse/National Fine) and metric thread sizes.
Tap and Drill Charts
These tap and drill bit charts will help you quickly identify the proper size drill bit for your tap on every job. Use our guide to identify the bits you'll need and make sure you’re drilling the correct hole size for clean threads every time.
NC-NF: Coarse and Fine Standard Fractional Sizes
| Tap Size | Drill Bit Size | Thread Standard |
|---|---|---|
| #0-80 | 3/64" | UNF (National Fine) |
| #1-64 | #53 | UNC (National Coarse) |
| #1-72 | #53 | UNF (National Fine) |
| #2-56 | #50 | UNC (National Coarse) |
| #2-64 | #50 | UNF (National Fine) |
| #3-48 | #47 | UNC (National Coarse) |
| #3-56 | #46 | UNF (National Fine) |
| #4-40 | #43 | UNC (National Coarse) |
| #4-48 | #42 | UNF (National Fine) |
| #5-40 | #38 | UNC (National Coarse) |
| #5-44 | #37 | UNF (National Fine) |
| #6-32 | #36 | UNC (National Coarse) |
| #6-40 | #33 | UNF (National Fine) |
| #8-32 | #29 | UNC (National Coarse) |
| #8-36 | #29 | UNF (National Fine) |
| #10-24 | #26 | UNC (National Coarse) |
| #10-32 | #21 | UNF (National Fine) |
| #12-24 | #16 | UNC (National Coarse) |
| #12-28 | #15 | UNF (National Fine) |
| 1/4-20" | #7 | UNC (National Coarse) |
| 1/4-28" | #3 | UNF (National Fine) |
| 5/16"-18 | F | UNC (National Coarse) |
| 5/16"-24 | I | UNF (National Fine) |
| 3/8"-16 | 5/16" | UNC (National Coarse) |
| 3/8"-24 | Q | UNF (National Fine) |
| 7/16"-14 | U | UNC (National Coarse) |
| 7/16"-20 | 25/64" | UNF (National Fine) |
| 1/2"-13" | 27/64" | UNC (National Coarse) |
| 1/2"-20 | 29/64" | UNF (National Fine) |
| 9/16"-12 | 31/64" | UNC (National Coarse) |
| 9/16"-18 | 33/64" | UNF (National Fine) |
| 5/8"-11 | 17/32" | UNC (National Coarse) |
| 5/8"-18 | 37/64" | UNF (National Fine) |
| 11/16"-11 | 19/32" | UNC (National Coarse) |
| 11/16"-16 | 5/8" | UNF (National Fine) |
| 3/4-10" | 21/32" | UNC (National Coarse) |
| 3/4-16" | 11/16" | UNF (National Fine) |
| 7/8-9" | 49/64" | UNC (National Coarse) |
| 7/8-14" | 13/16" | UNF (National Fine) |
| 1-8" | 7/8" | UNC (National Coarse) |
| 1-12" | 59/64" | UNF (National Fine) |
| 1-1/8"-7 | 63/64" | UNC (National Coarse) |
| 1-1/8"-12 | 1-3/64" | UNF (National Fine) |
| 1-1/4"-7 | 1-7/64" | UNC (National Coarse) |
| 1-1/4"-12 | 1-11/64" | UNF (National Fine) |
| 1-3/8"-6 | 1-7/32" | UNC (National Coarse) |
| 1-3/8"-12 | 1-19/64" | UNF (National Fine) |
| 1-1/2"-6 | 1-11/32" | UNC (National Coarse) |
| 1-1/2"-12 | 1-27/64" | UNF (National Fine) |
Metric Thread Sizes
| Tap Size | Drill Bit Size |
|---|---|
| M1.6 x 0.35 | 1.25mm |
| M1.8 x 0.35 | 1.45mm |
| M2 x 0.40 | 1.60mm |
| M2.2 x 0.45 | 1.75mm |
| M2.5 x 0.45 | 2.05mm |
| M3 x 0.50 | 2.50mm |
| M3.5 x 0.60 | 2.90mm |
| M4 x 0.70 | 3.30mm |
| M4.5 x 0.75 | 3.70mm |
| M5 x 0.80 | 4.20mm |
| M6 x 1.00 | 5.00mm |
| M7 x 1.00 | 6.00mm |
| M8 x 1.25 | 6.70mm |
| M8 x 1.00 | 7.00mm |
| M10 x 1.50 | 8.50mm |
| M10 x 1.25 | 8.70mm |
| M12 x 1.75 | 10.20mm |
| M12 x 1.25 | 10.80mm |
| M14 x 2.00 | 12.00mm |
| M16 x 2.00 | 14.00mm |
| M16 x 1.50 | 14.50mm |
| M18 x 2.50 | 15.50mm |
| M18 x 1.50 | 16.50mm |
| M20 x 2.50 | 17.50mm |
| M20 x 1.50 | 18.50mm |
| M22 x 2.50 | 19.50mm |
| M22 x 1.50 | 20.50mm |
| M24 x 3.00 | 21.00mm |
| M24 x 2.00 | 22.00mm |
| M27 x 3.00 | 24.00mm |
| M27 x 2.00 | 25.00mm |
| M30 x 3.50 | 26.5mm |
| M30 x 2.00 | 28.00mm |
| M33 x 3.50 | 29.50mm |
| M33 x 2.00 | 31.00mm |
| M36 x 4.00 | 32.00mm |
| M36 x 3.00 | 33.00mm |
| M39 x 4.00 | 35.00mm |
| M39 x 3.00 | 36.00mm |
Found your size, but still need to purchase a new drill bit and tap? Drill and tap kits for nearly every size are available from Drill America at Zoro.com, so you can always get what you need for the job at hand.
Related Products
While you're exploring the drill bits you need for your next project, check out these products from Drill America that make the job easier than ever. For example, their tap and drill bit sets contain a convenient range of common sizes, so you'll always have the tools you need within reach.
Finding the right tap and drill bit sizes for your business or jobsite doesn't have to be a frustrating or complicated experience. With the charts included here, you can quickly identify the supplies you'll need to finish the job efficiently and correctly.
Shopping for drill bits, tap and drill bit sets, and related products for your business? Find everything you need for your next job at Zoro.com!
Product Compliance and Suitability
The statements contained in this guide are intended for general informational purposes only. Such statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness, or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand, and follow all manufacturer instructions.
