METHOD OF PISTON RINGS PRODUCTION Russian patent published in 2015 - IPC F16J9/14 F02F5/00 

FIELD: process engineering.

SUBSTANCE: invention relates to production of piston ring with the butt. In production, circular metal body is coated with at least one hard ply in at least in area of its outer peripheral surface. Note here that said coating application, piston ring inner peripheral surface is processed, at least partially, by material removal with wall depth reduction. Material removal is made, starting from said butt, at periphery of 10-120 degrees, in particular, 90 degrees. At least inner peripheral surface of piston ring is coated with nitrated ply. The latter, right after coating of piston ring peripheral surface, is subjected to removal of material.

EFFECT: perfected method.

4 cl, 1 dwg