Seamless steel pipe wt class

According to the ANSI B36.10 america standard

Seamless steel pipe wt grade: Sch10, Sch20, Sch30, Sch40, Sch60, Sch80, Sch100, Sch120, Sch140, Sch160 ten grades;

1) ANSI B36.19 wall thickness grade: Sch5s, Sch10s, Sch40s, Sch80s (usually used for stainless steel) four grades;

2) According to the wall thickness of steel pipe, China, ISO, and Japan

3) The thickness of the pipe wall is expressed by the weight of the pipe, which divides the wall thickness of the pipe into three types:

a. Standard weight tube, expressed in STD
b. Thickened tube, expressed in XS
c. Extra thick tube, denoted by XXS.

For example:
For pipes with DN ≤ 250mn, Sch40 is equivalent to STD, DN<200mm pipe, Sch80 is equivalent to XS and sch20. These are the corresponding grades. The table can be found in millimeters. For example, DN200 sch20 wall thickness. The American standard thickness is 6.35 mm.