F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
F16J—PISTONS; CYLINDERS; SEALINGS
F16J9/00—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction
F16J9/26—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction characterised by the use of particular materials
B—PERFORMING OPERATIONS; TRANSPORTING
B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
B23P15/08—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass piston rings from several pieces