... pipes-Outside diameter (unit: mm)8,9.5,11,12,12.7,14.5,15.9,17,18,19,20,22,23,28 ... ,38,45,47,48,50.8,60,63,46,88.9,102,114,133,141,159,2192) Square pipe-Outside diameter ... (unit: mm)10×10,12×12,15×15,17×17,18×18,19×19,20×20,22×22,23×23 ... ) Outside diameter: ±0.15mm, b) Thickness: ±10% of wall thickness, c) Length: ±4.5-0mm8) Outer size can be manufactured according ...