Shafts Built Around the Fits That Matter
A shaft is a deceptively simple part — a row of diameters along a length — but its job lives in a few critical features: the bearing journals, the keyway or spline that transmits torque, the threaded ends, and the shoulders that locate everything. Get those right and the shaft drops into the assembly and runs true; get them wrong and it slips, runs out, or won't go on. We machine shafts around those fits, not just to the outline.
Custom Shaft Specifications
| Attribute | Capability |
|---|---|
| Materials | 1045 / 4140 / 4340 steel, 303/304/316 stainless, aluminium, brass — plus acetal, Delrin, nylon, PEEK for light-duty |
| Diameter range | ~Ø3–200 mm (larger on request) |
| Length | Short pins to long shafts (between-centres grinding) |
| Diameter tolerance | ±0.01–0.025 mm turned; ground to h6/k5/m6 |
| Surface finish | Down to Ra 0.2 µm on ground journals |
| Features | Keyways, splines, threads, cross-holes, flats, tapers, hollow bores |
| Heat treatment | Through-harden, induction-harden, nitride (as required) |
Geometric Accuracy We Hold
On a shaft the diameters are only half the story — what makes it run true is the geometric accuracy: concentricity, straightness and journal runout. This is where many shafts fail and where grinding between centres earns its place:
| Feature | Standard | Tight (ground) |
|---|---|---|
| Concentricity / coaxiality | ≤0.05 mm | ≤0.02 mm |
| Roundness | ≤0.05 mm | ≤0.02 mm |
| Straightness | ≤0.05 mm / 100 mm | ≤0.02 mm / 100 mm |
| Journal runout (TIR) | ≤0.02 mm | ≤0.01 mm |
| Surface finish (journals) | Ra 0.8–1.6 µm | Ra 0.2–0.4 µm |
| Keyway position | ±0.05 mm | ±0.02 mm |
| Thread class | 6g / 6H | 5g / 5H |
Splines & Threads — Cut to Standard
A shaft is only useful if its spline and thread match the mating part exactly — so we cut to the recognised standards (something most shaft pages never actually state):
- Splines: straight-sided and involute (DIN 5480 / ISO 4156), SAE, plus serrations — internal splines broached, external splines hobbed or milled.
- Threads: metric, UN/UNF, ACME / trapezoidal lead screws, BSP/NPT — cut to class.
- Keyways: to DIN 6885 / ISO 773, sized to the shaft diameter and your key.
Not sure which standard yours is? Send the mating gear, hub or nut — or the old shaft — and we identify and match it.
Shaft Types We Machine
- Stepped shafts — multiple diameters with located shoulders
- Keyed shafts — keyways to DIN 6885 / ISO 773 for torque transfer
- Splined shafts — straight or involute splines
- Threaded shafts & lead screws — metric, UN, ACME and custom threads
- Hollow / deep-bored shafts — gun-drilled, concentric bores (see our deep-hole shaft case)
- Drive shafts & spindles — including reverse-engineered replacements
How We Make Them
Shafts are CNC-turned for the diameters and features, milled for keyways and cross-holes, then ground on critical journals after any heat treatment for final tolerance and finish. For hardenable steels like 4140 we machine soft, harden, then finish-grind. Straightness, concentricity and runout are verified on inspection. See our CNC turning capability for the turning side.
Broken or discontinued shaft? Send it — even snapped in two. We reconstruct journals, keyway, threads and length and machine a drop-in replacement. See the reverse-engineered drive shaft case, or how to reverse engineer a shaft & keyway.
Typical Applications
- Drive shafts, axles and spindles
- Gearbox and conveyor shafts
- Pump and motor shafts
- Lead screws and actuator shafts
- Replacement shafts for discontinued machinery
Frequently Asked Questions
Yes. Send the shaft (even broken) or photos with key dimensions. We measure journals, keyway, threads, splines and length, rebuild it, and confirm critical fits before machining. No drawing needed.
Turned diameters to ±0.01–0.025 mm; ground journals to fit classes like h6/k5/m6 with low runout, finished after heat treatment.
1045/4140 steel (often hardened and ground), 303/304/316 stainless, 4340 for high loads, and aluminium or brass for light duty. Matched or upgraded to your load and environment.
Yes — we gun-drill long straight bores and turn the outside to the bore so the shaft runs concentric, for coolant-fed, drawbar, wiring or weight-saving shafts.
Quote a Custom Shaft
Drawing, sample or sketch — all accepted. Reply in 24h.