HHIP composite set of surface roughness standards features 30 specimens 7/8 inch x 3/8 inch of electroformed solid nickel. Each Type of surface finish is truly and consistently reproduced with a realistic idea of the feel, appearance and texture of the machined components. For quick and easy comparisons. Conforms to s.A.E and military specifications. Supplied with wallet, instructions and certificate. Micron inch AA product specifications: horizontal milling (6 specimens): 16, 32, 63, 125, 250 and 500; vertical milling (6 specimens): 16, 32, 63, 125, 250 and 500; turning (6 specimens): 16, 32, 63, 125, 250 and 500; plain grinding (6 specimens): 2, 4, 8, 16, 32 and 63; flat lapping (2 specimens): 2 and 4; external grinding (4 specimens): 8, 16, 32 and 63.