Characteristic
1. OD Tolerence: ±0.05mm for small pipe diameters(blow OD 15), for pipe diameters of 15 and above is ≤0.1mm.Smooth touching in the surface, without any ridges or unevenness.
2. The weld seam should be uniform and neat, the inner protrusion height ≤ 0.06mm. For pipes with a diameter of 9.5mm and above, the inner surface must be flattened without any protrusions.