The Captive Spares Problem
Much of what sits in an OEM spares catalogue is conventional machining — turned sleeves, milled brackets, ground shafts — sold at captive prices because the part number only exists in one catalogue. Industry comparisons put OEM spares around 65% above equivalent aftermarket pricing, and on simple machined parts the multiple is often far worse. Add a 12-week backorder and a single point of supply, and the "genuine part" starts costing more than money.
An OEM alternative done properly isn't a knock-off — it's the same engineering delivered without the catalogue premium. The geometry is taken from your sample or drawing, the material is matched or upgraded, and the critical fits are measured and documented before the part ships.
When an Alternative Makes Sense — and When It Doesn't
| Situation | Our honest advice |
|---|---|
| Simple machined part, big OEM markup | Strongest case — this is most of what we do |
| OEM backorder, machine waiting | Custom machining is often faster than the OEM's own queue |
| Single-sourced critical spare | Second source = negotiating power and supply security |
| Part under active warranty | Check your warranty terms first — we'll say so rather than sell you trouble |
| Safety-certified component | Keep the certified chain; we decline these rather than fake a cert |
| Cheap and available from the OEM | Buy the OEM part. We tell you when machining can't beat it |
What "equivalent" means here. Form: dimensions and tolerances from your sample or drawing. Fit: critical interfaces — bores, threads, mounting faces — measured against the original and documented. Function: material matched to the duty, or upgraded where the original was the weak point. What we never copy: brand names, logos, type plates or protected markings.
Typical OEM Alternatives We Machine
Shafts & sleeves
Ground journals, keyways and threads to the original fits — a classic captive part.
Machine brackets & mounts
Milled brackets sold at casting prices; machined from billet, often stiffer.
Rollers & guides
Conveyor and web-handling rollers with bearing seats and crowns matched.
Seal & bearing carriers
Precision bores and run-out held to seal-manufacturer spec.
Special fasteners
Odd-thread studs, shoulder bolts and custom nuts. See custom fasteners.
Adapters & fittings
Proprietary connectors reproduced or converted to standard. See adapters & fittings.
How It Works
- Send the part, drawing, or both — plus the OEM quote if you have it, so we can tell you honestly whether we beat it.
- We verify the geometry — sample measured on CMM, drawing rebuilt with tolerances. See RE from a sample for how dimensions are recovered.
- You approve the drawing — critical fits flagged; material match or upgrade options quoted side by side.
- We machine, measure, ship — inspection report with the part. MOQ 1; batches drop the unit price sharply.
If the OEM part isn't just expensive but gone — discontinued or the maker out of business — that's a different problem with a better solution: see discontinued parts and manufacturer out of business.
OEM Alternative Work
Parts machined as OEM alternatives — same geometry and function, without the OEM part-number premium:
The Quote That Starts the Search
What sets this page apart is proof, not just a lower price — we machine the equivalent and document the critical fits so you can show it matches, minus the part-number premium. The call usually comes after a quote that didn't sit right, or a lead time that holds the whole plant hostage to one badge. Here is who reaches us, and what finally tips them.
"The OEM wants $900 for what is plainly a $90 piece of machining, and I'm tired of paying it"
Send the part or photos with the OEM quote. We measure it, machine the equivalent in the same or better material, and document the critical fits so you can prove it matches. Much of what's sold as a captive spare is ordinary machining with a part-number premium bolted on — and that premium is exactly what you stop paying.
"The OEM backorder is 14 weeks and they're the only place that even lists the part"
A sole source isn't a real source when the line is down. We reproduce the part from your sample to the original form, fit and function — usually in a fraction of the backorder — and keep the CAD so the next one ships in days. The part number was theirs; the geometry is just geometry.
"One supplier quietly owns my uptime and I want a second source before it bites me"
Sensible — and best done before the breakdown, not during it. Send the captive parts on your critical list; we machine verified equivalents, document the fits, and hold the CAD so a repeat order is routine. You keep the OEM in the mix and stop being at their mercy on price or lead time.
"I just want the same part that works — without the badge and the markup"
That's the whole premise. We reproduce function and geometry to match your sample — never brand markings — verify form-fit-function, and supply material certs where it matters. Same part where it counts, MOQ 1, and you're buying from the shop that machines it rather than a captive catalogue.
What Buyers Search For Instead of the OEM Part
Frequently Asked Questions
When the geometry, material and tolerances match, the part performs the same — much of what OEMs sell as spares is conventional machining priced as a captive part. We verify form, fit and function against your sample: same dimensions, same or better material, critical fits measured and documented.
Owning equipment generally includes the right to repair it with parts from any source. Two caveats we flag honestly: parts under active warranty terms may be affected by third-party replacements, and safety-certified components should keep their certification chain. We reproduce function and geometry, never brand markings.
Often, yes — captive spare parts carry the OEM's margin, packaging and part-number premium. Industry comparisons put OEM spares at roughly 65% above equivalent aftermarket pricing, and simple machined parts can be multiples of that. Send photos and the OEM quote; we'll tell you honestly whether custom machining beats it.
Either. A drawing is fastest. With only the physical part, we measure it and rebuild the drawing — including tolerances inferred from the fits it runs in. With photos plus key dimensions we can usually still quote, then confirm geometry from the sample before machining.
It matches in form, fit and function, but we never reproduce brand names, logos or part numbers — that's the line between a legitimate equivalent and a counterfeit, and we don't cross it. Functionally the part is the same; cosmetically it's unbranded. If a marking is a genuine functional feature — an alignment mark, a flow arrow — we keep that.
We verify it so you don't have to guess. We measure your sample, document the critical fits on a drawing, and send it for your approval before machining — then inspect those fits on the first piece and supply the report on request. Order one to confirm it in the machine before committing to a batch; that's exactly what the single-piece price is for.
OEM Alternative Quote
Send the OEM quote too — we'll compare honestly.
// Qty & price
1 pc
Sample price
Confirm fit before a run
3–10
Unit price drops
Setup cost shared
10+
Best price
All tiers quoted upfront
- →No distributor — you pay the maker directly
- →CAD saved after first order — reorder anytime at lower unit price
support@ekinsun.ltd