remachining

Remachining is a manufacturing and repair process in which a component that has already undergone machining is machined again to restore, modify, or refine its dimensions, geometry, or surface quality. It is used to salvage worn parts, correct dimensional errors from initial manufacture, repair damaged features, or upgrade to tighter tolerances or different specifications without replacing the part.

The remachining toolkit includes subtractive processes such as turning, milling, drilling, boring, grinding, and finishing operations like honing, lapping, or superfinishing. Depending on the feature, processes may be used alone or in combination: for example re-boring a worn bore, re-cutting threads, resurfacing a seating surface, or reducing a diameter on a shaft to restore interference fits. Precision metrology and appropriate fixturing are essential due to accumulated tolerances, wear, and potential distortion from prior operations.

Materials are primarily metals, though plastics and composites can be remachined in some cases with suitable tooling, speeds, and feeds. Equipment ranges from conventional lathes and milling machines to CNC turning centers and grinding machines, often with specialized jigs, fixtures, and measurement devices to ensure accuracy.

Applications include salvage of aerospace, automotive, power-generation, oil and gas, and tooling components, refurbishment of mating surfaces, and rework of features to meet revised specifications. Remachining is also used in repair shops to extend part life or bring a worn feature back within tolerance.

Considerations include a cost-benefit assessment, as remachining adds cycle time and requires skilled tooling and measurement. Risks include potential loss of component integrity or surface quality if not performed correctly, making replacement sometimes more economical.