Seamless steel pipe wall thickness ranges from~2 mm up to 100 mm+(custom heavy-wall),defined by standard Schedule(SCH)series(ASME B36.10M)and direct mm specifications.
1.Standard Schedule(SCH)Series(Most Common)
SCH=wall‑thickness grade;higher SCH=thicker wall.
Thin‑wall(low pressure)
SCH 5S,SCH 10S,SCH 10,SCH 20
Typical WT:2.11–6 mm
Standard‑wall(general use)
STD,SCH 40,SCH 60
Typical WT:6–10 mm
Heavy‑wall(high pressure)
XS(SCH 80),SCH 100,SCH 120,SCH 140,SCH 160
Typical WT:8.5–13.5 mm
Extra‑heavy‑wall(extreme service)
XXS(double extra‑strong)
WT:15–60 mm+
2.Common Wall‑Thickness Ranges by Application(mm)
General fluid/structure(GB/T 8162/8163)
2.5–40 mm
High‑pressure boiler/heat exchanger(GB/T 5310)
4–70 mm+
Oil/gas line pipe(API 5L)
4–30 mm
Heavy‑wall custom
40–100 mm+(for high‑temp,high‑stress,or corrosion service)
3.Key Notes
For a given NPS/DN,OD is fixed;only WT changes with SCH.
Wall thickness is always specified as OD×WT(e.g.,114.3×6.02 mm=4"SCH 40).
Custom non‑standard thicknesses are available for special projects.
GB/T 7714
Li Changmu.Analysis of the Standard System and Wall Thickness Series for Steel Pipes[J].Steel Pipe,2018,47(02):68-73
MLA
Li,Changmu.“Analysis of Steel Pipe Standard System and Wall Thickness Series.”Steel Pipe,vol.47,no.2,2018,pp.68-73.
APA
Li,C.(2018).Analysis of steel pipe standard system and wall thickness series.Steel Pipe,47(2),68-73.
