GOLF CLUB SHAFT

摘要

PROBLEM TO BE SOLVED: To provide a golf club shaft significantly improved in strength and solidity by rifling metallurgically formed on the inner surface of the shaft. SOLUTION: A tubular material piece for manufacturing a golf club shaft comprises a base part 12 of uniform cross-sectional form in the lengthwise direction, a tip part 14 of uniform cross-sectional form in the lengthwise direction, and a taper part for connecting the base part 12 and the tip part 14. Rifling metallurgically formed on the inner surface of the material piece is extended over the whole of the base part 12 tip part 14 and tapered part. The golf club shaft manufactured of these material pieces is increased in strength and solidity as a direct result of internal rifling. A golf club shaft set is manufactured of a group of these tubular material pieces respectively with the same length and the same characteristic frequency. Specified parts are then selectively eliminated from the tip part and the base part.