Engineering tools

Trapezoidal Coiling Calculator

Developed by AbarTech / Mark Cragg·Version 1.1·Updated June 2026

A physics-based tool for calculating trapezoidal wire preform dimensions required to produce a finished rectangular-section ring. Built from elastic-plastic bending theory, with optional corrections for springback, Poisson effects, thermal expansion and coiling process parameters.

Results are a strong first-pass engineering estimate. As with any forming process, real production data should be used to validate and, where needed, calibrate the model to a specific machine and material — the calibration fields below are built for exactly that.

How to use this calculator

This is a working engineering tool rather than a simplified web widget. If you'd like help applying it to a specific job, material, or production line, get in touch and we'll work through it with you.

Free to use, provided as-is. This calculator is offered free of charge with no warranty or guarantee of accuracy, fitness for purpose, or suitability for any specific application. It is an engineering aid, not a substitute for qualified judgement, proper validation against production data, or your own design and quality processes. AbarTech Ltd accepts no liability for outcomes arising from its use. By using this tool you agree these results are estimates only and must be independently verified before being relied upon.

Basic Inputs

Outer Diameter, D_OD (mm)

Radial Thickness, T (mm)

Final Rectangular Width, W (mm)

Neutral Axis Shift, ΔR (mm)

Material Properties & Process Parameters

Material Type

Operating Temperature, T_op (°C)

Elastic Modulus, E (GPa)

Yield Stress, σ_y (MPa)

Poisson's Ratio, ν

Coiling Speed (m/min)

Coiling Tension (N)

Advanced Physics Corrections

Enable Poisson Effect Correction

Enable Thermal Effects

Enable Non-linear Strain Distribution

Enable Process-Specific Corrections

Springback Factor, K_sb

Work Hardening Exponent, n

Calibration Data (Optional)

Measured W_in (mm)

Measured W_out (mm)

Calibration Gain, k (0-1)

Machine ID

Results

Preform Dimensions

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Process Parameters

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Physics Analysis

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Validation & Confidence

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Usage notes: This calculator includes physics-based corrections for Poisson effects, thermal expansion, non-linear strain distribution, and process-specific factors. Results should still be validated against actual production data. Use the calibration fields to improve accuracy for a specific machine and setup.

Provided free, as-is, with no guarantee of accuracy. See full instructions and disclaimer.