Thread Pitch Calculator
Calculate thread pitch, threads per inch (TPI), and thread count for fasteners
Calculate Thread Specifications
Length of the threaded section to measure
Total number of threads in the measured length
If you know the TPI value, enter it here instead of length + thread count
Thread Calculations
⚠️ Engineering Safety Warning
• This calculator provides thread pitch measurements for reference purposes
• Always verify measurements with proper thread gauges or precision instruments
• Incorrect thread pitch can cause fastener failure and safety hazards
• Consider tolerance requirements and manufacturing standards
• Match thread specifications exactly for critical applications
• Consult engineering standards (ISO, ANSI, etc.) for official specifications
Example Calculation: M6 × 1.0 Thread Pitch
Measurement Scenario
Thread Type: Metric ISO thread
Measured Length: 20mm threaded section
Thread Count: 20 threads in that length
Expected Result: M6 × 1.0 (1.0mm pitch)
Thread Pitch Calculation
• Formula: P = L / n
• Thread Length (L) = 20mm
• Number of Threads (n) = 20
• Calculation: P = 20mm ÷ 20 = 1.0mm
• TPI Equivalent: 25.4 ÷ 1.0 = 25.4 TPI
Result: 1.0mm pitch confirms M6 × 1.0 thread
Standard Thread Pitches
Metric Coarse (mm)
Common Imperial TPI
UNC (Coarse)
Measurement Methods
Understanding Thread Pitch
What is Thread Pitch?
Thread pitch is the distance between identical points on two adjacent threads. It can be measured from crest to crest, root to root, or any corresponding points on consecutive threads. Thread pitch determines how fast a fastener advances when rotated and affects the thread's strength and holding power.
Measurement Techniques
- •Direct Method: Measure length and count threads (P = L / n)
- •TPI Method: Use threads per inch value (P = 1 / TPI)
- •Thread Gauge: Match with standard pitch templates
- •Multiple Thread: Measure several pitches for accuracy
Thread Pitch Formulas
P = L / n
P = 25.4 / TPI
n = L / P
- P: Thread pitch (mm)
- L: Thread length (mm)
- n: Number of threads
- TPI: Threads per inch
- 25.4: Conversion factor (mm per inch)
Applications
Quality Control
Verify thread specifications match design requirements
Fastener Identification
Determine thread standard and compatibility
Manufacturing
Set up tooling and cutting parameters