Custom Bore and Keyway NM Couplings
Two different shaft diameters can be identified as a bore pair, as shown by the catalogue's NM67-24/25 example. Keyway, fit, retention and hub material remain quotation-controlled.
Turn the request into a controlled configuration
Two different shaft diameters can be identified as a bore pair, as shown by the catalogue's NM67-24/25 example. Keyway, fit, retention and hub material remain quotation-controlled.
Photograph the marking and the complete assembly before disassembly. Measure the outside diameter, both hub lengths, bore pair, key details and ring geometry. Check the supplied catalogue rather than relying on colour alone. If a part is swollen, hardened or fragmented, describe the operating fluid, temperature, duty and time in service so the replacement question includes the likely failure mechanism.
The quotation should identify the coupling size, two finished bores, keyway standard and dimensions, fit, axial retention, hub material, flexible-ring material, any coating, quantity and inspection documents. Unknown values should be marked for confirmation. This prevents a provisional option from becoming an accidental product claim.
Why “spider” needs careful language
Buyers often search for a jaw coupling spider replacement. The supplied NM design, however, uses a continuous four-lobe NBR ring rather than the central star-shaped insert seen in many L-type couplings. Search language can be acknowledged without erasing the geometry difference.
Do not install a polyurethane ring merely because its hardness sounds suitable. Compatibility includes shape, dimensions, engagement, temperature, chemical environment, stiffness and torque rating. Obtain the supplier's written confirmation for the exact assembly.
Replacement and machining questions
Is the part universal?
No. Match the exact NM size and geometry; similarly named coupling families may use different rings and hubs.
What should I send with an RFQ?
Send model, both shafts, keyways, engagement, fit, duty, speed, quantity and destination.
Is hardness documented?
The supplied page states NBR but does not state hardness or temperature range. Request the material data with the quote.
Can the machine run without a guard?
No. Isolate the machine for inspection and restore an appropriate fixed guard before operation.