Shafts, gears, couplings and threaded fittings usually fail when tolerance, concentricity, material or surface finish is ignored. These examples show the types of parts EKINSUN can review from drawings or samples.
These images are not a fixed catalog. They show the type of work EKINSUN can quote from drawings, samples, photos, rough sketches, or existing parts.
Aluminium gear and shaft assembly. Cutting the teeth and the bearing journals about one axis is what keeps a gear running true — any error between the bore and the pitch circle turns into transmission error and noise once the pair is loaded.
Aluminium wheel spacers, made as a pair. A spacer sits inside a bolted joint and carries the whole clamp load of the studs, so it is the area of the two faces, not the outside diameter, that keeps the joint from going slack as the aluminium settles.
Small brass parts across a range of sizes. Brass is the default at this scale because it breaks its chips instead of stringing them, and a stringy chip is what wrecks an unattended run of parts this small.
Custom brass threaded fitting. On a parallel-thread fitting the thread only pulls the joint together — the seal is made on the seat or gasket face, so that face, not the thread, is the surface worth specifying.
Clutch components, including splined drive plates. A spline shares torque over many teeth at once instead of over one key, and it still lets the plate slide along the shaft while it is driving — which is exactly what a clutch plate has to do.
Shafts with a bore running down the axis. Past a certain depth-to-diameter ratio an ordinary drill wanders off centre and stops clearing its own chips, so the hole is produced with a guided, through-coolant deep-hole tool instead.
Shafts with machined keyways, run as a batch. The key is what carries torque between shaft and hub; the fit of the seat and the condition of its corners both matter, since a sharp keyway corner is where a loaded shaft starts to crack.
A large toothed ring, packed after machining. Large-diameter rings are the parts that move: the clamping force used while cutting and the way the ring is supported in transit both turn up afterwards as runout on the pitch circle.
BT40 milling chuck. A steep taper of this type is not self-holding — the drawbar is what keeps it seated — so any runout left in the taper or in the clamping bore is handed straight on to the cutting edge.
Machined gear discs in batch. The tooth edges get chamfered before the gear goes anywhere near a shaft: a raised burr on a flank is enough to stop a pair meshing sweetly, and it will not survive the first hour of running anyway.
Long stainless shaft. Length is the difficulty: a slender shaft deflects away from the tool unless it is supported along its span, and stainless work-hardens the moment feed drops, so the cut has to stay continuous.
Shafts turned in brass and in steel. The same drawing behaves differently in the two metals — brass cuts freely and holds size, while steel needs more cutting force and moves more as internal stress is released.
A set of shafts in several sizes. Turned shafts are made between their own centre holes, and those holes stay in the finished part — anyone regrinding a journal years later picks the shaft up on the same two points it was cut on.
Steel spur gears from one batch. A gear is only ever half of a pair: module and pressure angle have to match the wheel it runs against, so replacing one gear of a worn set means copying the tooth form of the survivor rather than designing a new one.
Stainless sensor fittings, trayed after machining. Stainless threads gall when two similar surfaces are torqued together dry, so the thread flanks and the sealing face are exactly the areas kept away from handling damage.
Stainless threaded couplings. What is left between the thread crest and the outside diameter is the whole strength of the part, so a coupling is sized by that wall — not by the thread, which anyone can copy off a table.
Stainless threaded shafts. Where a thread runs up to a shoulder the tool has to be let out somewhere: without a run-out or an undercut groove the last threads come out malformed, and the nut stops short of the face it was meant to seat against.
A turned tool holder body. Holders are judged on how little they move: the clamping bore, the locating face and the shank all have to be finished true to one axis, because whatever error remains is amplified at the tool tip.
Black anodised aluminium wheel spacer with marking. A ring this shape — large in diameter, short along the axis — is the awkward kind to hold: clamp it hard on the outside and the bore that has to fit the hub goes oval.
Wheel spacer with a branded outer face. A spacer moves the wheel outboard along its own axis, so anything added to that face — lettering, chamfer, relief — has to stay clear of where the wheel seats flat against it.
Stainless steel wheel spacers. Stainless is stiff and corrosion-resistant but far denser than aluminium, and where it meets an aluminium hub the two metals form a galvanic pair — which makes the mating faces the detail worth thinking about.
Clutch components, including splined drive plates. A spline shares torque over many teeth at once instead of over one key, and it still lets the plate slide along the shaft while it is driving — which is exactly what a clutch plate has to do.
Turned brass parts held one to a pocket for shipping. Laid out in a grid they can be counted at goods-in without unwrapping anything, which matters more on a delivery of several hundred small parts than any amount of outer packaging.
Machined brass parts set into cut foam for export. Brass is soft, and on a long transit parts knocking together mark exactly the surfaces that have to stay undamaged — threads, sealing seats, spanner flats — which is what the foam pockets keep apart.
Common situations where maintenance teams, gearbox shops and machine builders send us a shaft, gear or fitting instead of waiting on an OEM.
Send us the broken or worn shaft. We reverse-engineer it from the sample (no drawing needed), re-cut the keyways, splines, tapers and threads, machine it in 4140 / 4340 / 17-4 or stainless and heat-treat to match. MOQ 1, quoted in 12 hours from photos and key dimensions.
Send the worn gear (or the mating gear). We count teeth, measure the module/DP, pressure angle and bore, and cut a new spur, helical, bevel or worm gear by hobbing or gear milling — often saving well over half the cost of a new gearbox or assembly.
We machine custom shafts, spindles and pinion shafts with keyseats (broached), internal/external splines, retainer grooves, tapers and threads, then grind journals and thread-grind to tight tolerance. First article inspection, then repeat batches at tiered pricing.
We machine custom threaded fittings, couplings, adapters and worm/worm-wheel sets in brass, bronze, 304/316L or alloy steel, to any thread standard (BSP, NPT, metric, UN). EN 10204 3.1 material certs and inspection reports supplied on request.
Send a sketch, photo, old sample, or CAD file. Our engineers will review geometry, material, tolerance and finishing before quoting.
Upload SketchSend a drawing, sketch, sample or photo — reply within 12 hours. MOQ 1.