Abstract: Friction clutch plates have a first face exhibiting a surface finish of about Ra 0.5 to 0.9 and a second face having friction material secured thereto. The clutch plates are manufactured by rolling steel to a thickness of about 0.030 inches (0.76 mm) which exhibits a mill finish of about Ra 0.64 to 1.14. The rolled steel is then stamped to form circular clutch plate blanks. One surface is then smoothed, preferably by polishing, so that peaks and sharp points are flattened or removed. The resulting surface finish includes irregular relatively flat and smooth regions interspersed with and separating irregular recesses or pits and exhibits a surface finish of about Ra 0.5 to 0.9. Friction material is then secured to the opposite face of the clutch plates. The clutch plates are used in multiple plate friction clutch packs which are intended for use in dual clutch front and rear axle assemblies and motor vehicle transfer cases.

Abstract: Friction clutch plates have a first face exhibiting a surface finish of about Ra 0.5 to 0.9 and a second face having friction material secured thereto. The clutch plates are manufactured by rolling steel to a thickness of about 0.030 inches (0.76 mm) which exhibits a mill finish of about Ra 0.64 to 1.14. The rolled steel is then stamped to form circular clutch plate blanks. One surface is then smoothed, preferably by polishing, so that peaks and sharp points are flattened or removed. The resulting surface finish includes irregular relatively flat and smooth regions interspersed with and separating irregular recesses or pits and exhibits a surface finish of about Ra 0.5 to 0.9. Friction material is then secured to the opposite face of the clutch plates. The clutch plates are used in multiple plate friction clutch packs which are intended for use in dual clutch front and rear axle assemblies and motor vehicle transfer cases.