... diameter, inch (mm)Diameter tolerance, inch(mm), +/-Permissible variaton in wall thickness, %, +/-<1 (25.4)0.004 (0.102)101~1. ... strength δbpsi (MPa), ≥Yield strength δ0.2, psi (MPa),≥Elongation in 1"/2" gage length, %, ≥RO5200/RO540030000 (207)20000 (138)25RO525240000 ...