Abstract: A gear having a high fatigue strength can be produced relatively inexpensively. The gear is produced by plastic working using a steel material containing C.ltoreq.0.01 wt %, Si.ltoreq.1 wt %, 0.05 wt %.ltoreq.Mn.ltoreq.0.5 wt %, P.ltoreq.0.1 wt %, S.ltoreq.0.03 wt %, 0.02 wt %.ltoreq.sol.Al.ltoreq.0.1 wt %, 0.8 wt %.ltoreq.Cu.ltoreq.1.7 wt %, and 0.02 wt %.ltoreq.Ti.ltoreq.0.1 wt %, the balance being Fe and inevitable elements. The gear is subjected to soft nitriding, serving as artificial aging, after a solution treatment. The resulting gear has a sufficiently deep, surface hardened layer. Further, the gear may be produced inexpensively since the simultaneous performance of the artificial aging and soft nitriding saves energy.

Abstract: A piston head for an internal combustion engine is provided containing a polished nickel plated layer formed in the piston top and an anodized layer formed on at least the lower part of the uppermost piston ring groove in order to reduce the adverse affects of excessive thermal conditions on the member.

Abstract: A V-pulley is adapted for a continuously variable transmission which uses a chain belt composed of a plurality of chain blocks connected in its longitudinal direction, and a pair of V-pulleys operatively connected to each other through the chain belt. The V-pulley comprises a pair of conical pulley faces that the chain belt contacts, each of which is provided with a rough surface and a combination pattern of abrasion-prone and abrasion-resistant sections alternatively arranged at intervals shorter than the contact length and width of each chain block.