Wexmar provides custom coupling machining for OEMs and maintenance teams that need rigid couplings, clamp couplings, coupling hubs, sleeves and adapters made to print. Our Canastota, New York shop produces CNC machined couplings on Mazak and Doosan lathes with live tooling, and on Swiss machines for small instrument couplings, with bores and keyways held concentric to each other.
What couplings do and who buys them
A coupling connects two shafts to transmit torque, typically a motor to a pump, gearbox, spindle or encoder. Rigid couplings require the shafts to be aligned. Flexible couplings use hubs that connect through an elastomer, disc, gear or grid element. In both cases, the machined hub or sleeve must have a bore that fits the shaft, a keyway or clamp that carries torque, and a pilot or face that runs true. Our coupling customers include pump and fluid power OEMs, power transmission and gearbox builders, motor and drive integrators, automation and motion control companies, and defense programs replacing legacy hardware. We also rebore and re-key catalog hubs to non-standard shaft sizes.
Custom coupling machining process
Couplings are turned parts. We bore, turn and face on our Mazak lathes, including the Nexus QT200, Nexus 250, Nexus 450-II and Multiplex 6300Y, and on Doosan Lynx 2100A machines. Live tooling and Y-axis let us mill keyways, drill and tap set screw holes, cut clamp slots and drill cap screw holes in the same chucking as the bore. That keeps keyway symmetry and set screw location referenced directly to the bore axis. The twin-spindle Multiplex finishes both bores of a rigid coupling in one cycle for good bore-to-bore concentricity.
Small instrument and encoder couplings under 32 mm diameter run on our Maier MLK-32 Swiss machines. Couplings with split clamp bodies, flange bolt patterns on several faces, or square hubs can go to our Mazak horizontal machining centers with 4th-axis rotaries. See CNC turning and horizontal CNC milling.
Coupling materials
- Steel: 1018, 1045, 4140 pre-hard and 4340 for high-torque hubs.
- Stainless: 303, 304, 316 and 17-4 PH for washdown and corrosive service.
- Aluminum: 6061-T6 and 7075 for low-inertia motion control couplings.
- Others: bronze, ductile iron bar, titanium and engineered plastics.
Critical coupling features and how we hold them
- Bore fit: bored to ANSI/AGMA clearance or interference fits, or ISO H7 and similar, measured at both ends for taper.
- Keyways: cut to ANSI B17.1 or ISO/DIN 6885 width and depth, with keyway symmetry controlled to the bore centerline.
- Bore-to-bore concentricity: both bores finished in one setup or on the twin-spindle for rigid couplings.
- Face and pilot runout: faces and pilots cut in the same chucking as the bore.
- Set screw and clamp features: tapped holes located over the keyway or at 90 degrees as specified, and clamp slots sized for proper closure.
Typical tolerances and finishes
| Feature | Typical tolerance | Tighter on request |
|---|---|---|
| Bore diameter | +0.001 / -0.000 in | +0.0005 / -0.000 in |
| Bore-to-bore concentricity | 0.001 in | 0.0005 in |
| Keyway width | +0.002 / -0.000 in | +0.001 / -0.000 in |
| Keyway symmetry | 0.002 in | 0.001 in |
| Face runout | 0.001 in | 0.0005 in |
| Bore finish | 63 Ra | 32 Ra |
These are typical values. Interference-fit bores for heavy-duty hubs are sized from your shaft tolerance, and we confirm the fit before machining.
Secondary operations
Heat treat, black oxide, zinc plating, anodizing and passivation are performed through qualified outside processors. Dynamic balancing, when specified, is arranged through outside processors as well. We can rebore and re-key customer-supplied coupling hubs, which is often the quickest route when a catalog hub is available but the bore is not.
Quantity patterns
Coupling work splits between urgent maintenance replacements of 1 to 5 pieces, prototype hubs for new drive packages, and OEM production lots of 50 to 500. Programs are kept on file for repeat orders.
Inspection
Bores are measured with calibrated bore gages and checked with plug gages, keyways with gage blocks and keyway gages, and runout and concentricity with indicators on a precision arbor. Our Brown & Sharpe CMMs verify bolt patterns and hole positions. AS9102-format first articles, material certs and lot traceability are available. See inspection and quality.
Getting a quote
Send a drawing with shaft sizes, keyway specs, material and quantity, or send the catalog hub you want modified. You can upload a drawing for an instant estimate, and an estimator will confirm pricing. Or call (315) 400-2654. Related: custom shafts.