JIS type 2 titanium is cold–worked for work–hardening, and is commercially available (G2W), and this material is used to produce implants. In this study, the mechanical characteristics and corrosion resistance of this work–hardened material (G2W) were compared with those of JIS type 2 titanium (G2), JIS type 4 titanium (G4), and JIS SSH4650–60E (G5). The following results were obtained: ①The tensile strength was highest in G5, and lowest in G2. No marked difference was observed between G2W and G4. ②The proof stress was highest in G5, and lowest in G2. No significant difference was noted between G2W and G4. ③The elongation was highest in G2, and lowest in G5. No significant difference was present between G2W and G4. ④The fracture toughness showed a significant difference between G2 and G2W, whereas no significant differences were observed among G2W, G4, and G5. ⑤The maximum bending load at an inclination angle of 30° was lowest in G2, and no significant differences were noted among G2W, G4, and G5. ⑥The hardness was highest in G5, and lowest in G2. No significant difference was present between G2W and G4. ⑦The released volume of titanium was highest in G5, and lowest in G2W. The released volume was higher in G4 than in G2. Vanadium and aluminum were released from G5. ⑧Work–hardened titanium (G2W) showed mechanical characteristics equivalent to those of G4, and excellent corrosion resistance, and is considered to be useful as an implant material