Twist Rate Calculator

This calculator determines the twist rate (TPI - turns per inch) of a helical structure based on its physical dimensions.

Input Parameters

Calculation Results

Calculation Results

Twist Rate (TPI): --

Helix Turns: --

Pitch Circle Diameter (PCD): -- mm

Calculation Formula

TPI = π × Helix Diameter / Helix Length

Where:
TPI = Turns Per Inch
π = 3.14159265359
Helix Diameter = Overall diameter of the helix
Helix Length = Length of the helical path

Twist Rate Calculator Usage Guide

Learn how to use the Twist Rate Calculator and understand the calculations behind it

How to Use This Calculator

  1. Enter the Wire Diameter in millimeters (mm) - the diameter of your wire material
  2. Enter the Helix Length in millimeters (mm) - the length of the complete helical turn
  3. Enter the Helix Diameter in millimeters (mm) - the overall diameter of the helix
  4. Click the "Calculate" button to compute the twist rate and other parameters
  5. Use the "Reset" button to clear all inputs and start over

Understanding the Calculations

The calculator uses the formula:

TPI = π × Helix Diameter / Helix Length

Where TPI (Turns Per Inch) represents how many complete turns of the helix occur in one inch of length. This value is crucial in applications like wire rope construction, spring manufacturing, and textile production.

Example Application

For instance, if you have a wire with 2mm diameter and it forms a helix with a 10mm diameter and 50mm length, the calculator will show:

  • Twist Rate: 0.6283 TPI
  • Helix Turns: 25 turns
  • Pitch Circle Diameter: 10.00 mm

This means that for every inch of vertical travel, the wire makes approximately 0.63 complete turns around the helix axis.