Sizing + Coining

Sintering leaves a part close to its final shape but not always at its final dimension, so a part that needs a closer fit is re-pressed in a sizing die that brings its bore and outside diameter to the drawing and leaves a smoother surface than the as-sintered part carries. Coining is the same operation taken further, pressing the part to its finished form and finish rather than machining it there. Symmco holds sizing tolerances as tight as 0.001" where the application calls for it, and its 17 sizing presses run alongside the compaction fleet so that a sized bearing does not wait on an outside operation.

Where Symmco quotes an ID or OD minimum and maximum for a stock size, those figures are the dimensions the part is sized to, measured before any press fit or assembly, so they describe the part as it leaves the sizing press rather than as it sits in a housing after installation. The stock catalogue lists each stock size by nominal I.D., O.D. and length, with general dimensional tolerance tables by size range, and the product family pages list the same nominal dimensions online by part number. Ask Symmco for the sized minimum and maximum on any part where the fit matters.