Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

NPT Threads - Taps and Drill Sizes

NPT - Briggs Standard Pipe threads - Taps and Drill Sizes.

The NPT - National Pipe Taper Threads - is based on the Briggs Standard Pipe Thread.

Drill sizes for Briggs Standard Pipe taps for direct tapping without reaming are indicated below:

NPT Threads - Taps and Drill Sizes
Size Taps
(inches)
TPISize Drill
(inches)
1/8 27 21/64
1/4 18 27/64
3/8 18 9/16
1/2 14 11/16
3/4 14 29/32
1 11.5 1 1/8
1 1/4 11.5 1 15/32
1 1/2 11.5 1 23/32
2 11.5 2 3/16
2 1/2 8 2 9/16
3 8 3 3/16
3 1/2 8 3 11/16
4 8 4 3/16
  • TPI = threads per inch
  • 1 inch = 25.4 mm

Related Topics

Related Documents

Search

Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .

Citation

This page can be cited as

  • The Engineering ToolBox (2008). NPT Threads - Taps and Drill Sizes . [online] Available at: https://www.engineeringtoolbox.com/briggs-standard-pipe-taps-d_1125.html [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter

















































11.4.12

.