Thread Pitch Converter
Convert between different thread measurement systems: Metric pitch, Imperial TPI, and more.
Conversion Results
From:
To:
Formula Used:
Common Thread Standards
| Thread Size | TPI | Pitch (mm) |
|---|---|---|
| M6 | 25.4 | 1.0 |
| M8 | 20 | 1.25 |
| M10 | 17 | 1.5 |
| 1/4 UNC | 20 | 1.27 |
| 1/4 UNF | 28 | 0.91 |
About Our Thread Pitch Converter
Our Thread Pitch Converter is an essential tool for engineers, mechanics, and DIY enthusiasts who work with threaded fasteners. It allows for quick and accurate conversion between different thread measurement systems, ensuring you get the right fastener for your project.
Understanding Thread Measurements
Thread measurements can be expressed in different ways, depending on the standard being used:
- Metric Pitch: The distance between adjacent threads, measured in millimeters (mm).
- Threads Per Inch (TPI): The number of threads occurring in one inch of the fastener length, common in imperial systems.
- Imperial Pitch: The distance between adjacent threads, measured in inches.
Conversion Formulas
TPI to Metric Pitch (mm): Pitch (mm) = 25.4 ÷ TPI
Metric Pitch (mm) to TPI: TPI = 25.4 ÷ Pitch (mm)
TPI to Imperial Pitch (inches): Pitch (inches) = 1 ÷ TPI
Imperial Pitch (inches) to TPI: TPI = 1 ÷ Pitch (inches)
Key Features:
- Convert between TPI (Threads Per Inch) and metric pitch (mm)
- Convert between TPI and imperial pitch (inches)
- Reference table of common thread standards
- Precise calculations for machining and fabrication tasks
- User-friendly interface for quick conversions
How to Use:
- Select the desired conversion type from the dropdown
- Enter the value you wish to convert
- Click "Convert" to see the results
- Reference the common thread standards table for quick comparisons
Applications:
Mechanical Engineering: Design and specification of threaded components and fasteners.
Automotive Repair: Identifying the correct replacement bolts, nuts, and screws for vehicles.
Machining: Setting up lathes and thread-cutting equipment to the correct specifications.
DIY Projects: Finding compatible fasteners when mixing metric and imperial components.
3D Printing: Designing threaded connections for printed parts.
Thread Standards
Different regions and industries use various threading standards:
- Metric (ISO): Used worldwide, particularly in Europe and Asia. Designated with an "M" followed by the diameter in mm (e.g., M6 × 1.0).
- Unified Thread Standard (UTS): Common in the US and Canada. Includes UNC (coarse), UNF (fine), and UNEF (extra fine) threads.
- British Standard Whitworth (BSW): Traditional British standard, still used in some applications.
- National Pipe Thread (NPT): Used for pipe fittings, with a tapered thread for sealing.
Whether you're working on precision machinery or a simple home repair, our Thread Pitch Converter ensures you get the right measurements every time. Convert between thread standards with confidence!
Frequently Asked Questions
How do I identify the thread pitch of an existing bolt?
You can measure the thread pitch using a thread pitch gauge, which is a specialized tool with teeth that match standard thread pitches. Alternatively, you can count the number of threads in a one-inch section (for TPI) or measure the distance between adjacent thread peaks with a caliper (for metric pitch). For more accurate results, measure across several threads and divide by the number of thread spaces.
Can I use a metric fastener in an imperial threaded hole?
Generally, metric and imperial threads are not compatible, even when the diameters seem similar. However, some combinations might seem to fit but will likely be loose or bind. For critical applications, it's best to use the correct thread type. If necessary, you can re-tap the hole to convert it from one standard to another, or use thread adapters for certain combinations.
What does the "M" stand for in thread specifications like M8×1.25?
The "M" designates a metric thread according to the ISO metric thread standards. In the example M8×1.25, "M" indicates metric, "8" is the nominal outer diameter in millimeters, and "1.25" is the thread pitch in millimeters (the distance between adjacent thread peaks).