A tap drill size chart is an essential tool for anyone working with standard threads, whether it’s for a home DIY project or in a professional workshop. Standard threads are a series of ridges or protrusions that are cut or rolled into the surface of a fastener or component, allowing it to be fastened to another piece by screwing the two pieces together. The tap drill size chart provides the recommended sizes for drilling holes to accommodate standard threads, ensuring a proper fit and optimal performance.
Factors to Consider When Selecting a Tap Drill Size
When selecting a tap drill size, it’s important to consider the type of material you’re working with, as well as the size and type of thread being used. Different materials, such as metals and plastics, have different properties and may require different tap drill sizes. Similarly, different thread sizes and types, such as UNC, UNF, and NPT, have different requirements for tap drill sizes.
Using a Tap Drill Size Chart
To use a tap drill size chart, first determine the size and type of thread you’ll be working with. Then, refer to the chart to find the recommended tap drill size for that thread. It’s important to note that the tap drill size chart is only a guide, and actual results may vary based on the specific material and application.
Importance of Using the Correct Tap Drill Size
Using the correct tap drill size is essential for ensuring that the threads are properly formed and the fastener or component functions as intended. A tap drill size chart is an invaluable resource for anyone working with standard threads and can save time and frustration by providing the recommended sizes for a variety of different threads and materials [1].
Tap Drill Size Chart for Standard Threads
Below is a tap drill size chart for standard threads:
| Thread Size | Tap Drill Size (inches) |
| #4-40 | #31 (.116) |
| #6-32 | #29 (.136) |
| #8-32 | #28 (.164) |
| #10-24 | #25 (.190) |
| #10-32 | #24 (.201) |
| 1/4-20 | #7 (.201) |
| 1/4-28 | #6 (.207) |
| 5/16-18 | #11 (.193) |
| 5/16-24 | #10 (.205) |
| 3/8-16 | #9 (.254) |
| 3/8-24 | #8 (.257) |
| 7/16-14 | #14 (.273) |
| 7/16-20 | #13 (.278) |
| 1/2-13 | #19 (.256) |
| 1/2-20 | #18 (.262) |
Remember, this tap drill size chart is just a guide and actual results may vary based on the specific material and application. Always use caution and proper safety measures when working with tools and materials.
Summary
A tap drill size chart is an essential tool for anyone working with standard threads. It provides the recommended sizes for drilling holes to accommodate standard threads, ensuring a proper fit and optimal performance. When selecting a tap drill size, it’s important to consider the type of material you’re working with and the size and type of thread being used.