The Problem
A gear in a drive train had worn or failed, and the part was no longer available — no drawing, no supplier, just the old gear. The customer needed not one but a batch of spares, so the machine would never again be stranded by a single component. The job wasn't "copy this shape," it was "reproduce a gear that meshes correctly with its mating gear, every time."
Why a gear is reproducible: its geometry is defined by standard parameters and a mathematical involute tooth form. We don't copy worn teeth — we derive the correct gear from its numbers, so even a worn or chipped sample yields a perfect new one.
How It Was Made
1 — Recover the gear parameters
From the original gear we established the parameters that define it: number of teeth, module (or diametral pitch), pressure angle, helix (none, for spur), face width, and the bore and keyway. The mating gear and the centre distance served as independent cross-checks. The full method is described in our guide to replacing a discontinued gear.
2 — Machine the batch
With the parameters confirmed, the gears were cut as a batch so every piece is identical — the tooth form generated to the standard involute, bores and keyways held to a consistent fit on the shaft.
3 — Harden for wear life
Power-transmission gears need surface hardness to survive. The gears were made in a suitable steel and hardened so the new spares match — or outlast — the original's service life. Material and hardening are matched to the application and confirmed with the customer.
The Workflow
Measure the original gear
Teeth counted; module, pressure angle, bore and keyway recovered and cross-checked.
Confirm mesh data
Verified against the mating gear and centre distance before cutting.
Cut the batch
Identical gears machined to the standard tooth form, bores and keyways consistent.
Harden & inspect
Hardened to spec; tooth form and bore inspected across the batch.
Outcome
A set of identical steel spur gears that mesh like the original — and a shelf of spares so the same failure never stops the machine again. Reproducing gears, shafts and fittings from a sample, with no drawing, is core EKINSUN work — whether you need a single replacement or a production batch.
Have an obsolete gear? Send the gear (worn or chipped is fine) and its mate if possible. We recover the parameters and cut new ones — one or a batch. Email [email protected] or message us on WhatsApp.