a swash plate type compressor having a cylinder block with cylinder bores disposed parallel to the axis of the cylinder block . a rotary shaft rotatably mounted within the cylinder block carries an aluminum swash plate . the swash plate is fixed in the rotary shaft and has two facial surfaces and an end surface . the swash plate has a coating preferably between 0 . 8 to 2 . 5 microns , of a tin / cobalt coating of at least 0 . 2 wt % cobalt and the balance being tin . a piston reciprocally fitted within the cylinder bore contains shoes which slideably intervene between the piston and the swash plate facial surfaces and reciprocate the piston and the swash plate facial surfaces and reciprocate the pistons by rotation of the swash plate . the coating on the swash plate permits the use of low silicon alloy aluminum without the need of metal plating or high finish polishing .