Pipe Schedule Dimensions

Dimensions, not pressure ratings

What this is

A browsable table of standard steel pipe dimensions as defined by ASME B36.10M (carbon steel) and ASME B36.19M (stainless steel). Outside diameter is fixed per nominal size (NPS) and constant across schedules; wall thickness increases with schedule number. The inside diameter that feeds a velocity, pressure-drop or slurry-line calculation is computed from these two — enter it into the Pipe Velocity, Pipe Pressure Drop, Pipe Flow Rate or Pipe Head Loss calculator.

Inside diameter is derived

Inside diameter is computed as ID = OD − 2 × wall and is the only derived value in this table. It is not a tabulated standard figure. It is shown below in a muted style and tagged derived so it is never mistaken for a tabulated standard figure.

Dimensions by nominal size

Wall thickness is the governing standard value. Inside diameter is derived (OD − 2 × wall). Schedules not defined for a size are omitted.

Schedule designations

• •Standard (STD) equals Schedule 40 up to and including NPS 10; above NPS 10, STD is a flat 9.53 mm (0.375 in) wall and diverges from Schedule 40. Extra-Strong (XS) equals Schedule 80 up to and including NPS 8; above NPS 8, XS is a flat 12.70 mm (0.500 in) wall and diverges from Schedule 80. The Schedule 40 and Schedule 80 columns here carry the schedule-number wall, not the STD/XS constant.
• •Double Extra-Strong (XXS) is a thickness designation, not a schedule number. ASME B36.10M does not tabulate an XXS thickness above NPS 12, so those cells are blank.

What is not published

• •NPS 1/8, 1/4, 3/8 — Sch 160 and XXS wall thicknesses. Single-sourced: these heavier thicknesses appear in some commercial charts but NOT in ASME B36.10M Table 1, so the governing standard does not corroborate them. Held per doctrine §2.3 (single source is not validated).
• •Weight per unit length (kg/m and lb/ft) — entire column. Not two-source-validated in this build. Per the PIPE-SCHEDULES-001 ruling the weight column ships only if two-source-validated per cell, else the whole column HOLDs. Held pending a corroborated weight dataset.
• •Schedule and size combinations the standard does not define are left blank rather than estimated.

Boundaries and exclusions

• •Dimensions only — no pressure ratings, no allowable-stress or wall-thickness design.
• •No material-selection guidance and no manufacturer endorsement.
• •Confirm any value against the governing standard and vendor data before procurement or detailed design.

Sources

• •Governing standard. ASME B36.10M-2004, Welded and Seamless Wrought Steel Pipe, Table 1 (carbon steel); ASME B36.19M (stainless steel — identical OD per NPS and identical wall values for the schedules in scope, with an "S" suffix on the schedule label)
• •Corroborating reference. Crane Technical Paper No. 410 (TP-410), Appendix B pipe data; corroborated additionally by Perry's Chemical Engineers' Handbook standard-pipe-dimension tables

The corroborating references reproduce the ANSI/ASME B36.10 dimensional standard rather than measuring independently. For a defined standard no independent measurement is possible; corroboration confirms faithful transcription. Disclosed per the doctrine, as with the NIST/CoolProp same-lineage flag. Outside diameter and wall thickness are matched exactly to the standard's stated precision; the two unit columns (mm and in) are the standard's own rounded expressions of the same governing value.