Medical instrument, medical device, method of manufacturing medical instrument, and metal article

Medical ocular forceps comprising:

• a tubular shaft made of either an austenitic stainless steel or a cobalt-chromium-nickel alloy and having a thickness-wise diameter of not greater than 0.5 mm;
• and
• a core rod axially reciprocatingly inserted inside the tubular shaft, the core rod configured with a forceps tip exposed through a tip end of the tubular shaft and openable/closable by axial reciprocation of the core rod;
• wherein
• the tubular shaft is exterior-surface nitrided, carburized, or carbonitrided to impart to the tubular shaft a predetermined flexibility satisfying the following three-point bending test conditions under an ambient temperature of 20° C.±0.5° C.:
• with the tubular shaft supported on two fulcrums spaced 30 mm apart, the compression load applied orthogonally to the longitudinal center of the tubular shaft to yield 3-mm downward deflection is between 0.5N and 1.0N.