Thread Pitch Calculator

Thread Parameters

Type of thread standard
Thread diameter or size designation
Thread fit class
Length of threaded portion

Calculation Results

0

Thread Pitch Calculator: Your Complete Guide to Thread Measurements

Accurately calculating thread pitch is essential for engineers, machinists, and manufacturers. Our Thread Pitch Calculator helps you determine the correct thread specifications for various applications.

Understanding Thread Pitch Calculations

Proper thread pitch calculation is crucial for several reasons:

  • Compatibility: Ensures proper thread engagement
  • Strength: Determines load-carrying capacity
  • Manufacturing: Guides production processes
  • Quality Control: Maintains standards compliance
  • Assembly: Ensures proper fit and function

How to Use the Thread Pitch Calculator

  1. Select Thread Type: Choose the thread standard
  2. Enter Thread Size: Input the thread diameter
  3. Choose Thread Class: Select the fit class
  4. Specify Length: Enter thread length
  5. Click Calculate: Get thread specifications

Thread Pitch Calculation Formulas

Metric Thread Pitch:
Pitch = 1 / TPI
Unified Thread Pitch:
Pitch = 1 / (Threads per inch)
Where:
TPI = Threads per inch
Pitch = Distance between thread crests

Common Thread Standards

  • Metric (ISO):
    • M1.6 to M100
    • Standard and fine pitch
    • International standard
  • Unified (UNC/UNF):
    • #0 to 4 inches
    • Coarse and fine series
    • Common in US/Canada
  • British (BSW/BSF):
    • 1/8" to 6"
    • Whitworth and fine series
    • UK standard
  • Acme:
    • 1/4" to 6"
    • Power transmission
    • High load capacity

Real-World Examples

Example 1: Metric Thread

Thread Type: Metric (ISO)
Size: M10
Class: 2
Length: 20mm
Results:
- Pitch: 1.5mm
- TPI: 16.93
- Major Diameter: 10mm
- Minor Diameter: 8.376mm

Example 2: Unified Thread

Thread Type: Unified (UNC)
Size: 1/2-13
Class: 2
Length: 1 inch
Results:
- Pitch: 0.0769 inches
- TPI: 13
- Major Diameter: 0.5 inches
- Minor Diameter: 0.4219 inches

Frequently Asked Questions

What's the difference between thread pitch and TPI?
Thread pitch is the distance between thread crests, while TPI (Threads Per Inch) is the number of threads in one inch. They are inversely related: Pitch = 1/TPI.
How do I choose the right thread class?
Class 1 is for loose fits, Class 2 for general purpose, and Class 3 for precision fits. Consider the application requirements, load conditions, and assembly needs.
What affects thread strength?
Thread strength depends on material, pitch, engagement length, and thread class. Coarse threads are stronger in shear, while fine threads are better for tension.
How do I measure thread pitch?
Use a thread pitch gauge, measure the distance between thread crests, or count threads per inch. For metric threads, measure the distance between adjacent threads.
What are common thread applications?
Common applications include fasteners, power transmission, fluid connections, and precision positioning. Each application may require different thread standards and classes.

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