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Free to use, provided as-is. No warranty or guarantee of accuracy or fitness for purpose — an engineering aid for the round-stock-to-section conservation relationship only, not a substitute for trial passes and your own process validation. AbarTech Ltd accepts no liability for outcomes arising from its use.

Wire Profile Rolling Calculator

Keystone Section — Round Stock → Trapezoidal (Bevelled) Profile
Developed by AbarTech / Mark Cragg  ·  Version 1.0  ·  Updated June 2026
Solves the verified conservation-of-volume relationship between round feed stock and a finished keystone-section wire profile, for area, length, and reduction. Does not attempt to predict roll groove design, spread distribution between passes, or work-hardening/anneal points — those depend on equipment and process specifics this tool can't see. See the notes at the bottom.
How to use this calculator →
01

Keystone Section Geometry geometry verified

02

Bevels & Corner Radii geometry verified

Outer (thick-edge) corners
Inner (thin-edge) corners
Chamfer vs fillet aren't interchangeable here A flat chamfer removes the same area at a given leg length regardless of whether it's cut at an outer or inner corner — the two corner angles (90°±θ/2) are symmetric about 90°, and chamfer area depends on sin(φ), which shares that symmetry. A radius fillet does not share it: the same radius removes a different area at the outer corner versus the inner corner, because the cotangent term in the fillet formula isn't symmetric the same way. So with fillets, which corners you select and what radius you give them actually matters, in a way it doesn't for chamfers.
03

Round Stock & Reduction conservation law verified

Length relationship
No assumed reduction target There's no baked-in "recommended" RA% here. Total area reduction is an equipment/process design choice, not a physical constant — you set it from your own process knowledge, the calculator just does the conservation arithmetic honestly. The "theoretical minimum diameter" row is the absolute floor (zero reduction, pure reshaping) — useful as a sanity bound, not a target.
04

Process Notes judgement, not calculated

Back tension & fill Back tension on a passive (pull-through) stand genuinely does influence how reduction splits between elongation and lateral spread — confirmed from direct process experience, not a public formula. It's a real lever for adjusting corner/groove fill. This calculator doesn't quantify it; treat it as a live process variable you control on the line, not a number this tool can give you.
Cumulative cold work & inter-anneal Whether inter-process annealing is needed isn't just a function of total area reduction — roll diameter changes contact arc length and therefore deformation time, which affects work hardening independently of RA%. That's too dependent on your specific tooling for this calculator to predict responsibly, so it deliberately doesn't try. Track cumulative cold work against your own process experience for the actual mill geometry in use.
Scope This is the conservation-law layer only: section geometry and the round-stock ↔ finished-profile area/length relationship, both checked against independent methods. It does not model roll groove design, pass-by-pass spread, or how many stands/passes a given reduction needs — that's a separate, harder problem that would need real reference data (your own groove drawings or measured pass results) before anything could be trusted in a live tool.
Verification loop Since you measure thick edge and included angle inline during production, that's a direct way to check this calculator's geometry against real output — feed in what your gauge reads and compare to what's predicted here from the round stock and roll setup.

Profile rolling converts round wire stock into shaped cross-sections by compression between profiled rolls. The keystone (trapezoidal) section is the standard form for retaining ring and circlip wire — the taper corrects for the shorter inner-radius path when the wire is coiled. This calculator solves the area conservation relationship between round stock and the finished keystone section, with bevel/chamfer corrections. AbarTech Ltd designs and manufactures wire rolling and forming equipment as part of complete retaining ring production lines, based in Dyserth, North Wales.

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