ASTM A554

- is an internationally recognized standard of the American Society for Testing and Materials. It contains standard specifications for welded stainless steel mechanical tubing of various cross-sectional shapes (round; rectangular, square - for profile tube; etc.).

Round pipe ovality - is the difference between the maximum and minimum outside diameters at any cross-section. For pipes with a specified wall thickness of more than 3% of the outside diameter, there is no additional tolerance for ovality.

For stainless steel pipes with an outside diameter of up to and including 127 mm, the ovality tolerance is twice the outside diameter tolerance of the pipes, applied as half plus (+) and half minus (-) to pipes with a specified pipe wall thickness of 3% or less of the specified outside diameter. The average value of the maximum and minimum outside diameter readings must be within the outside diameter tolerances, as shown in the table below.

For pipes with a diameter over 127 mm and up to and including 406.4 mm, when the specified wall thickness is equal to or less than 3% of the outside diameter, the out-of-roundness shall not exceed 1.5% of the specified outside diameter.

Pipes manufactured according to this standard are intended for use in decorative, structural engineering solutions, such as exhaust pipes, etc. They are used in those structures where appearance, high mechanical properties, and/or corrosion resistance are required simultaneously.

This specification covers the dimensions of both welded and cold formed tubes and mechanical tubes up to 406.4 mm in diameter and with a wall thickness of 0.51 mm.

Optional additional requirements are possible and must be specified when ordering production.

**Table: ASTM A-554 - Tolerances: Diameter, Wall Thickness, Out-of-Roundness (Round Stainless Steel Pipe) – All Conditions Except Pipes with Removed Bead**
Outer diameter, mm	Wall thickness in mm	Outer diameter ± mm
up to 12.7	0.51 - 1.24	0.10
12.7 - 25.4	0.51 - 1.65	0.13
12.7 - 25.4	more than 1.65 to 3.40	0.25
more than 25.4 - 38.1 incl.	0.64 - 1.65	0.20
more than 25.4 - 38.1 incl.	more than 1.65 to 3.40	0.25
more than 38.1 - 50.8 incl.	0.64 - 1.24	0.25
more than 38.1 - 50.8 incl.	more than 1.24 to 2.11	0.28
more than 38.1 - 50.8 incl.	more than 2.11 to 3.78	0.30
more than 50.8 - 63.5 incl.	0.81 - 1.65	0.30
more than 50.8 - 63.5 incl.	more than 1.65 to 2.77	0.33
more than 50.8 - 63.5 incl.	more than 2.77 to 4.19	0.36
more than 63.5 - 88.9 incl.	0.81 - 4.19	0.36
more than 63.5 - 88.9 incl.	more than 4.19	0.51
more than 88.9 - 127.0 incl.	0.89 - 4.19	0.51
more than 88.9 - 127.0 incl.	more than 4.19	0.64
more than 127.0 - 190.5 incl.	1.24 - 6.35	0.64
more than 127.0 - 190.5 incl.	more than 6.35	0.76

PLEASE NOTE !

Wall thickness tolerance ± 10% of the specified wall thickness.

The pipes are manufactured from flat rolled steel by automatic welding without the addition of filler metal. The pipes must have one of the following shapes - round, square, rectangular or special. Thermal analysis must be performed, with several grades of steel meeting the required chemical composition for carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, titanium, columbium and tantalum.

This International Standard has been developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Committee on Technical Barriers to Trade.