... psi275,000 psi 29,000,000psi0.277 lbs/cubicinchAISI302100,000-180,000psi50,000-150,000psi55-60%29,000,000psi286 lbs/cubicinchAISI304100 ... ,000-180,000psi50,000-150,000psi55-60%29,000,000psi286 lbs/cubicinchAISI31690 ... ,000 psi270,000 psi 29,000,001psi0.275 lbs/cubicinch China polished and durable steel ball (SGS approved )