Wexmar offers custom impeller machining for open and semi-open impellers with straight or simple vane geometry. We are a precision CNC machine shop in Canastota, New York, and we produce CNC machined impellers by turning the hub and shroud profile on our lathes and cutting the vanes on 3- and 4-axis horizontal machining centers. We want to be clear about fit before you send a drawing: closed impellers, and blades with twisted or compound-curved surfaces that need continuous multi-axis contouring, are outside what we produce. For open designs with radial or straight-swept vanes, we are a practical, direct source.
What impellers do and who buys them
An impeller transfers shaft power into a fluid. Vane count, vane height and the bore fit to the shaft determine flow, head and balance. Our impeller customers are typically:
- Pump and fluid power OEMs replacing castings with machined parts for small runs
- Mixer, agitator and blower builders
- Maintenance and repair buyers needing replacement impellers from a drawing or sample
- Defense and government programs with build-to-print impellers of open design
How our custom impeller machining works
Turning the blank
The hub bore, back face, outside diameter and hub profile are turned on our Mazak or Doosan lathes. Holding the bore and back face in one chucking gives the square, concentric datum everything else depends on. Keyways are machined to standard in the same sequence.
Horizontal milling the vanes
The turned blank moves to a Mazak horizontal machining center, located on the bore and back face. The 4th axis indexes each vane position so pitch spacing is set by the machine, not by a fixture. Straight radial vanes, straight-swept vanes and flat-faced vanes of constant thickness are well suited to this method. Pallet changers let us load the next part while one is cutting, which helps on production lots. Read more on our CNC milling page.
What we do not machine
We do not produce closed (shrouded both sides) impellers, radial compressor wheels with twisted blades, or airfoil vane forms that require simultaneous multi-axis contouring. If your design is one of these, we will tell you at the quote stage.
Typical impeller materials
- 304, 316 and 17-4 PH stainless for water, chemical and sanitary service
- Bronze and brass for marine and general pump duty
- 6061 and 7075 aluminum for blowers and lightweight rotors
- Carbon and alloy steel for slurry and heavy-duty mixers
- Engineered plastics for corrosive or low-weight service
Critical features and how they are held
- Bore fit: finish bored to the shaft fit on the lathe, often held to a slip or light press fit.
- Bore to OD runout: bore and OD are finished in the same setup to limit imbalance at speed.
- Vane position and thickness: indexed by the 4th axis from the keyway or bore datum, with uniform thickness checked on the CMM.
- Back face flatness and squareness: faced in the bore setup so the impeller runs true against the shaft shoulder.
Typical impeller tolerances and finishes
| Feature | Typical tolerance | Tighter on request |
|---|---|---|
| Hub bore | +/-0.0005 in | +/-0.0003 in |
| Outside diameter | +/-0.002 in | +/-0.001 in |
| Bore to OD runout | 0.002 in TIR | 0.001 in TIR |
| Vane angular spacing | +/-0.1 deg | +/-0.05 deg |
| Vane thickness | +/-0.003 in | +/-0.002 in |
| Machined surface finish | 63 to 125 Ra | 32 Ra on selected faces |
These are typical values for open impellers. Vane depth, material and wall thickness change what is practical, and the quote states what we will hold.
Secondary operations
Dynamic balancing, heat treat, passivation, anodizing and coatings are completed through qualified outside processors. Where balancing requires material removal, we can plan drill-out locations with you in advance.
Quantity patterns
Machined impellers make the most sense from one-off replacements up to a few hundred pieces per year, where casting tooling is hard to justify. Repeat orders run from saved programs and fixtures.
Inspection
Bore size, runout, vane spacing and profile are verified on our Brown and Sharpe CMMs. FAI in AS9102 format, CMM reports, material certs and heat-lot traceability are available. See inspection and quality.
Getting a quote
Send a drawing or STEP model with material, quantity and shaft fit. You can upload a drawing for an instant estimate, and an estimator will confirm whether the vane geometry fits our process before pricing. Questions are welcome at (315) 400-2654.