ASME B36.19M is specifically tailored for stainless steel. Because stainless steel offers superior corrosion resistance, thinner walls can often be used safely. Our manufacturers can produce seamless and welded pipes to meet industry requirements. Contact us market@htpipe.com for more information and a free quote!
Dimensional Tolerances
ASME B36.19 refers to ASTM A999 or ASTM A530 for tolerances. Generally, the wall thickness at any point shall not be more than 12.5% under the nominal wall thickness specified.
ASME B36.19 vs. ASME B36.10M
| Difference | ASME B36.19 | ASME B36.10M |
| Material | Stainless Steel | Carbon & Alloy Steel |
| Thin Wall Options | Includes 5S and 10S | Usually starts at Sch 10 or 20 |
| Large Diameter WT | Sch 40S/80S may differ from 40/80 | Standard weights for heavy industry |
| Corrosion Allowance | Minimal (Material is inherently resistant) | High (Requires thicker walls for rust) |
Frequently Asked Questions (FAQ)
Q: Why is there no Sch 160 in ASME B36.19?
ASME B36.19 only covers up to Sch 80S. If an application requires thicker walls (like Sch 160 or XXS) for stainless steel, engineers refer to the dimensions in ASME B36.10M.
Q: Does the standard apply to both 304 and 316?
Yes. ASME B36.19 defines geometric dimensions. It applies to all stainless steel grades, including 304/L, 316/L, 321, and Duplex steels.
Q: Is NPS the same as the actual Outside Diameter?
No. For NPS 1/8 through NPS 12, the NPS is a "name" and does not match the OD. For NPS 14 and larger, the OD is exactly equal to the NPS x 25.4 mm.
ASME B36.19 Dimension Table (mm)
| Nominal Pipe Size | OD(mm) outside diameter | Sch5S (mm) | Sch10S (mm) | Sch40S (mm) | Sch80S (mm) | Sch160S (mm) | |
| DN | NPS | ||||||
| 6 | 1/8 | 10.3 | 1.24 | 1.73 | 2.41 | 3.15 | |
| 8 | 1/4 | 13.7 | 1.65 | 2.24 | 3.02 | 3.68 | |
| 10 | 3/8 | 17.1 | 1.65 | 2.31 | 3.2 | 4.01 | |
| 15 | 1/2 | 21.3 | 1.65 | 2.11 | 2.77 | 3.73 | 4.78 |
| 20 | 3/4 | 26.7 | 1.65 | 2.11 | 2.87 | 3.91 | 5.56 |
| 25 | 1 | 33.4 | 1.65 | 2.77 | 3.38 | 4.55 | 6.35 |
| 32 | 1 1/4 | 42.2 | 1.65 | 2.77 | 3.56 | 4.85 | 6.35 |
| 40 | 1 1/2 | 48.3 | 1.65 | 2.77 | 3.68 | 5.08 | 7.14 |
| 50 | 2 | 60.3 | 1.65 | 2.77 | 3.91 | 5.54 | 8.74 |
| 65 | 2 1/2 | 73 | 2.11 | 3.05 | 5.16 | 7.01 | 9.52 |
| 80 | 3 | 88.9 | 2.11 | 3.05 | 5.49 | 7.62 | 11.13 |
| 90 | 3 1/2 | 101.6 | 2.11 | 3.05 | 5.74 | 8.08 | |
| 100 | 4 | 114.3 | 2.11 | 3.05 | 6.02 | 8.56 | 13.49 |
| 125 | 5 | 141.3 | 2.77 | 3.40 | 6.55 | 9.53 | 15.88 |
| 150 | 6 | 168.3 | 2.77 | 3.40 | 7.11 | 10.97 | 18.26 |
| 200 | 8 | 219.1 | 2.77 | 3.76 | 8.18 | 12.7 | |
| 250 | 10 | 273.1 | 3.40 | 4.19 | 9.27 | 12.7 | |
| 300 | 12 | 323.9 | 3.96 | 4.57 | 9.53 | 12.7 | |
| 350 | 14 | 355.6 | 3.96 | 4.78 | 9.53 | 12.7 | |
| 400 | 16 | 406.4 | 4.19 | 4.78 | 9.53 | 12.7 | |
| 450 | 18 | 457 | 4.19 | 4.78 | 9.53 | 12.7 | |
| 500 | 20 | 508 | 4.78 | 5.54 | 9.53 | 12.7 | |
| 550 | 22 | 559 | 4.78 | 5.54 | |||
| 600 | 24 | 610 | 5.54 | 6.35 | 9.53 | 12.7 | |
| 650 | 26 | 660 | |||||
| 700 | 28 | 711 | |||||
| 750 | 30 | 762 | 6.35 | 7.92 | |||
