ASME B36.19
Stainless steel pipe — sizes and schedules
Sets the sizes and wall thicknesses of stainless steel pipe, including the light-wall "S" schedules — 5S, 10S, 40S and 80S.
- Dimensional standards
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is ASME B36.19?
ASME B36.19 is the standard for stainless steel pipe dimensions: outside diameters and the "S" wall schedules 5S, 10S, 40S and 80S. Schedule 40S equals Schedule 40 up to NPS 10 and 80S equals Schedule 80 up to NPS 8; above those sizes the stainless schedules are thinner. Carbon and alloy steel pipe uses ASME B36.10.
ASME B36.19 at a glance
| Product | Welded and seamless wrought stainless pipe |
|---|---|
| Schedules | 5S, 10S, 40S, 80S |
| Companion | ASME B36.10 for carbon and alloy steel pipe (Sch 10 – 160, STD, XS, XXS) |
Schedule 40S vs 40 — where they differ
Same OD; the wall differs only in larger sizes.
| NPS | Sch 40S wall | Sch 40 wall |
|---|---|---|
| 10" | 9.27 mm | 9.27 mm |
| 12" | 9.53 mm | 10.31 mm |
| 14" | 9.53 mm | 11.13 mm |
How to write ASME B36.19 on a purchase order
Name the product, size, material specification and grade, the dimensional standard and the certificate. An example line:
Illustrative only — sizes, tests, inspection level and any project values come from your purchase specification.
ASME B36.19 edition and verification status
Which edition we have confirmed, and what is still being checked before any numerical requirement is published here.
| Current edition | Not yet confirmed against the publisher listing |
|---|---|
| Full-text verification | In progress — numerical requirements are not published on this page |
| Edition on your order | The edition named in your purchase order or design code governs — confirm it with your enquiry |
What to know before ordering to ASME B36.19
The points that decide whether material to ASME B36.19 is accepted at inspection.
- Outside diameters are the same as B36.10 for the same NPS.
- 10S and 40S are the common stainless schedules.
- Heavier walls (Sch 160, XXS) come from B36.10.
Products made to ASME B36.19
How ASME B36.19 fits into an order
A purchase order line is only complete when it names the material standard, the dimensional standard and the inspection document. Miss one and the mill, the inspector and the buyer can each read the order differently.
Standards used with ASME B36.19
Same family
ASME B36.19 — questions buyers ask
What is ASME B36.19?
ASME B36.19 is the standard for stainless steel pipe dimensions: outside diameters and the "S" wall schedules 5S, 10S, 40S and 80S. Schedule 40S equals Schedule 40 up to NPS 10 and 80S equals Schedule 80 up to NPS 8; above those sizes the stainless schedules are thinner. Carbon and alloy steel pipe uses ASME B36.10.
Is Schedule 40S the same as Schedule 40?
Up to NPS 10, yes. From NPS 12 upward Schedule 40S is thinner than Schedule 40.
Why does stainless pipe use S schedules?
Stainless is more corrosion resistant and costlier, so lighter walls (5S, 10S) are common; B36.19 defines those.
Does ASME B36.19 specify the material?
No. ASME B36.19 sets dimensions; the material comes from a separate specification such as ASTM A182, A105 or B564 for flanges, or A403 and B366 for fittings. A complete order names both.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026