Wexmar provides custom sprocket machining for roller chain drives, conveyors and special equipment. Our Canastota, New York shop turns and bores sprocket blanks and hubs on CNC lathes and mills tooth forms on 4-axis horizontal machining centers for prototype and low-volume CNC machined sprockets. For production tooth cutting that requires hobbing, we route the work through qualified outside processors. We are a direct shop and every quote is reviewed by an estimator.
What sprockets do and who buys them
A sprocket engages a chain to transmit motion and torque. Tooth form, pitch diameter and bore-to-tooth runout determine how smoothly the chain runs and how long it lasts. Typical buyers include:
- Power transmission and conveyor OEMs needing non-standard bores, hubs or tooth counts
- Packaging, agricultural and material handling equipment builders
- Maintenance and repair buyers replacing obsolete or modified sprockets
- Defense and government programs with build-to-print sprockets
How our custom sprocket machining works
Turning blanks and hubs
Our Mazak and Doosan lathes turn the outside diameter, hub, chamfers and bore in one chucking, which ties the tooth circle to the bore axis. Keyways are machined to standard, and live tooling drills set screw and bolt holes. Many customers buy finished, bored and keyed blanks from us for tooth cutting elsewhere, or modify stock sprockets by reboring, hub turning or adding bolt patterns. See CNC turning.
Milling tooth forms
For prototypes, replacements and low volumes, we mill sprocket teeth on our Mazak horizontal machining centers, indexing each tooth with the 4th axis from the bore datum. This works well for standard ANSI roller chain pitches and for special tooth forms, larger pitches and segmented or split sprockets. See CNC milling.
Hobbing for production
Gear cutting and hobbing are not offered in-house. When a production quantity makes hobbing more economical, we machine the blank complete and have teeth cut through qualified outside processors.
Typical sprocket materials
- 1045 and 4140 steel for general and heavy-duty drives, often tooth hardened
- 303 and 316 stainless for food, washdown and corrosive environments
- 6061 and 7075 aluminum for lightweight, low-load drives
- Engineered plastics such as acetal and UHMW for quiet idlers
Critical features and how we hold them
- Bore and keyway: bored to the shaft fit and keyed to standard, with the keyway centered on the bore.
- Tooth circle runout: teeth are indexed from the finished bore to hold radial runout.
- Tooth spacing: set by 4th-axis indexing, checked over pins.
- Hub face runout: hub faces are turned with the bore so the sprocket runs flat against its shoulder.
Typical tolerances and finishes
| Feature | Typical tolerance | Tighter on request |
|---|---|---|
| Bore diameter | +/-0.0005 in | +/-0.0003 in |
| Keyway width | +0.002 / -0.000 in | +0.001 / -0.000 in |
| Tooth radial runout to bore | 0.003 in TIR | 0.0015 in TIR |
| Measurement over pins | Per ANSI B29.1 class | Customer tighter limit |
| Hub face axial runout | 0.002 in TIR | 0.001 in TIR |
| Tooth flank finish | 63 to 125 Ra | 63 Ra |
Values are typical for machined sprockets. Tooth count, pitch and material affect what is practical, and the quote confirms each feature.
Design notes
If you are buying blanks for outside hobbing, call out the outside diameter, bore and face as datums, and specify stock allowance for tooth cutting. For milled teeth, a standard ANSI tooth form or a clear tooth profile on the drawing avoids ambiguity. Split sprockets need bolt hole positions tied to the tooth pattern so halves mate without a step at the joint.
Secondary operations
Induction or flame hardening of teeth, through hardening, black oxide, zinc plating and nickel plating are completed through qualified outside processors. We schedule the outside work and inspect parts on return.
Quantity patterns
Milled sprockets fit quantities from one to a few dozen. Blanks and hubs run from prototype lots to production releases of several hundred, with teeth hobbed through qualified outside processors where volume supports it. Related parts include pulleys.
Inspection
Bore, keyway and runout are checked with gages and our Brown and Sharpe CMMs, and tooth form is verified over pins and on the Mitsubishi optical comparator. FAI in AS9102 format and material certs are available.
Getting a quote
Send the drawing or chain size, tooth count, bore and quantity. You can upload a drawing for an instant estimate, and an estimator will confirm price and lead time. Call (315) 400-2654 to discuss a sprocket.