Wire Profile Rolling Calculator — Guide

What this tool solves

Given the cross-section of a keystone (trapezoidal) wire profile, this calculator works out the round feed-stock diameter needed to roll it, and the area reduction, elongation, and length relationship that goes with it. The underlying relationship — cross-sectional area × length is conserved as wire passes through rolls — is the rolling industry's own "law of constant volume," the same conservation principle the wire drawing calculator already relies on for area-to-area reduction.

Reading the section geometry

The keystone section is defined by three numbers, matching how it's actually measured and controlled on the line:

The thin edge t isn't entered directly — it's derived:

t = T − 2h·tan(θ/2)

If t comes out ≤ 0, the angle is too large for that height/thick-edge combination and the section has collapsed past a triangle — the calculator will flag this rather than show a nonsense result.

Bevels — chamfer or fillet

Bevelled retaining ring wire has a corner treatment at the inner edge, outer edge, or both — on one face or both (single or double bevel). The calculator handles this as four independent corner checkboxes (outer-top, outer-bottom, inner-top, inner-bottom), plus a choice of treatment type:

• Flat chamfer — a leg-length cut, the same leg length removes the same area whether it's at an outer or inner corner (the two corner angles are symmetric about 90°, and chamfer area depends on sin, which shares that symmetry).
• Corner radius (fillet) — a rounded corner. Unlike the chamfer, the same radius removes a different area at an outer corner versus an inner corner, because the corner angles there are 90°+θ/2 and 90°−θ/2 respectively, and the fillet formula isn't symmetric around 90° the way the chamfer one is.

If your corner radii are all roughly the same (the common case), just enter the same value in both the outer and inner radius fields — the calculator will still correctly account for the fact that each removes a slightly different area; you don't need to work that out by hand.

Round stock & reduction

Two ways to use this section, picked with the radio toggle:

• I know my rod diameter — enter your round stock size, get the resulting area reduction, elongation, and true strain.
• I want to target a reduction % — enter a target reduction, get the round stock diameter required to hit it.

There's no built-in "recommended" reduction percentage. Total area reduction is your process design choice, not a physical constant — the calculator just does the conservation arithmetic honestly once you've decided. The theoretical minimum diameter row shown alongside is the zero-reduction floor (round stock with exactly the same area as the finished section) — a sanity bound, not a target; you can't roll to a finished area larger than your starting stock.

Worked example

What this tool deliberately leaves out