When can I replace just the spider?
A jaw coupling typically uses two hubs and a flexible insert called a spider. Identify the series and size from the part markings or drawing, then check that both hubs are serviceable. Ask the supplier to confirm the insert geometry and material or hardness. Matching colour and outside diameter alone cannot establish fit. Some designs allow insert replacement with the hubs in place. Check the procedure for the exact series.
When should I request new hubs or a complete assembly?
Ask for a hub or assembly review if the jaws or shaft attachment are damaged, or if the original coupling cannot be reliably identified. Provide the shaft diameters and tolerances on both sides, keyway or clamping details, the distance between shaft ends and the space around the coupling. If the insert wears repeatedly, have the maintenance team check alignment and installation spacing before ordering the same part again.
What should a replacement RFQ include?
State the equipment and duty, running torque, speed, starting or shock loads, and relevant temperature or oil exposure. Include the original part number or a nameplate photo, drawing revision, required quantity and destination city or port. Buyers in India, Thailand and Vietnam can use the same list. Ask the supplier to confirm fit and whether the quote covers an insert, hubs or a complete assembly.