GITNUX REPORT 2024

Tap Drill Size Chart

The Tap Drill Size Chart provides corresponding drill sizes in millimeters for various thread sizes ranging from 4-40 to 1/2-13.

Author: Jannik Lindner

First published: 7/17/2024

The Tap Drill Size Chart provides a reference for the appropriate drill size in inches for various tap sizes typically used in machining and metalworking applications. The chart includes tap sizes such as 4-40, 6-32, 8-32, 10-24, 12-24, 1/4-20, 5/16-18, 3/8-16, and 1/2-13, along with their corresponding drill sizes in millimeters. This information is essential for ensuring proper thread creation during the tapping process.

Chart Data

Tap Size (Thread Size) Drill Size (inches)
4-40 3.3 mm
6-32 5 mm
8-32 7 mm
10-24 8.5 mm
12-24 10.2 mm
1/4-20 13.5 mm
5/16-18 18 mm
3/8-16 21 mm
1/2-13 26 mm

Conclusion

The Tap Drill Size Chart provides the corresponding drill sizes in inches for various tap sizes (thread sizes), ranging from 4-40 to 1/2-13. The chart serves as a useful reference for selecting the appropriate drill size when tapping holes in different materials.

FAQ

What is a tap drill size?

A tap drill size refers to the drill bit size that is used to create a hole in a material before tapping threads into it.

How do you determine the tap drill size for a specific thread size?

The tap drill size for a specific thread size can be determined using standard tables or formulas that provide the recommended drill sizes based on the thread size and type of material being tapped.

Why is it important to use the correct tap drill size?

Using the correct tap drill size is important to ensure that the threads are securely and accurately formed in the material, preventing issues such as stripped threads or thread engagement problems.

Can a tap drill size be larger than the recommended size?

It is not recommended to use a tap drill size that is larger than the recommended size, as it can result in incomplete or weak threads that may not provide the necessary strength or stability.

Are there different tap drill size standards for different countries?

Yes, there are different tap drill size standards used in different countries, such as the Unified Thread Standard (U.S.), British Standard Pipe (BSP), and Metric thread sizes, each with their own corresponding tap drill sizes.