Free calculators, built from real production work

A growing set of practical engineering tools, built from the same calculations we use ourselves on the shop floor — not generic textbook reference charts. Free to use, with full disclaimers on each tool.

Wire forming

Trapezoidal Coiling Calculator

Calculates the trapezoidal wire preform dimensions needed to produce a finished rectangular-section coiled ring, with springback, Poisson and thermal corrections.

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Spring design

Spring Rate Calculator

Spring rate, deflection and stress checks for compression, extension and torsion springs from standard wire and coil geometry.

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Wire production

Wire Drawing Calculator

Area reduction, true strain and draw stress for round wire drawing — single-pass check or a full multi-pass schedule with annealing points flagged.

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Wire production

Wire Profile Rolling Calculator

Round stock to keystone (trapezoidal) section — verified area, reduction and elongation relationship, with bevel/chamfer corrections for finished retaining ring wire.

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Machining

Thread Root Relief & Dual-Index Calculator

Real thread dimensions for Metric/UN and Whitworth threads, plus a dual-index pass solution for when your insert's nose radius is smaller than the standard root radius — corrects depth without over-cutting.

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All tools on this page are provided free of charge, as-is, with no warranty or guarantee of accuracy or fitness for purpose. Each calculator includes its own full disclaimer. If you'd like engineering support applying any of these to a specific job, get in touch.