NM Coupling Bore And Keyway RFQ Guide
A model number alone is not enough for a finished-bore quotation. Provide both shaft diameters, keyway width/depth or standard reference, fit preference, hub orientation and any shoulder or axial-position constraints.
Why Bore Range Is Only A Starting Point
The model table gives a minimum and maximum bore range, but the final bore must still leave suitable hub geometry for the requested keyway and fit. Special bores near the upper end of the range deserve drawing review before release.
Keyway Information
State the keyway size or the shaft standard used. If the two shafts differ, each hub can require different machining. Include any taper, spline or non-standard interface explicitly instead of assuming the standard keyway.
Fit And Axial Position
Tell the supplier whether the hub is a clearance, transition or interference-fit requirement and how it locates axially. A shoulder, retaining arrangement or hub overhang can affect the approved drawing.
Inspection Requirements
Where needed, state bore tolerance, keyway inspection, concentricity/runout expectations and material/finish requirements in the purchase specification. Do not rely on a generic catalogue page to define project-specific inspection.
RFQ Checklist
- NM model
- Both shaft diameters
- Keyways or splines
- Fits and axial position
- Speed, torque and application
- Quantity and inspection requirements
