Thread Pitch Calculator
Calculate thread pitch, major diameter, minor diameter, and thread depth for metric and standard threads. This tool is essential for machinists, engineers, and manufacturing professionals.
Metric
M Series
Standard
UNC / UNF
Pipe
NPT / BSP
Thread Dimensions
Thread Profile Visualization
What is Thread Pitch?
Thread pitch is the distance between corresponding points on adjacent threads. It is a critical dimension in threading that determines the fit and strength of threaded connections. For metric threads, pitch is measured in millimeters, while for standard (inch) threads, it's often expressed as threads per inch (TPI).
Thread Calculation Formulas
The following formulas are used for thread calculations:
- Pitch (P): P = 1 / TPI (for inch threads)
- Major Diameter (D): Nominal diameter of the thread
- Pitch Diameter (Dp): D - 0.6495 × P
- Minor Diameter (Dn): D - 1.299 × P
- Thread Depth (H): 0.6495 × P
- Lead Angle: arctan(P / (π × Dp))
Note: For metric threads, the pitch is directly specified. For standard threads, pitch is calculated from TPI.
Thread Standards
| Thread Type | Pitch (mm) | TPI | Usage |
|---|---|---|---|
| M10 × 1.5 | 1.5 | 16.93 | Standard metric |
| M12 × 1.75 | 1.75 | 14.51 | Standard metric |
| UNC 1/4-20 | 1.27 | 20 | Unified coarse |
| UNF 1/4-28 | 0.91 | 28 | Unified fine |
| NPT 1/2-14 | 1.81 | 14 | Pipe thread |
How to Use This Calculator
- Select the Thread Type (Metric, Standard, or Pipe)
- Enter the Nominal Diameter of the thread
- Enter the Thread Pitch (for metric) or TPI (for standard)
- Select the Thread Class for tolerance grade
- Click Calculate to see the results
- All thread dimensions will be displayed in the results grid
Tip: Use the thread profile visualization to understand the thread geometry better.