Cold-rolled ERW mechanical tubing
ASTM A513 Type 2
An as-welded route using cold-rolled starting material, commonly considered when surface and dimensional expectations exceed a hot-rolled route.
On this page
The short answer
Type 2 is the as-welded ERW route made from cold-rolled strip. Compared with Type 1, the starting material typically brings a cleaner surface and tighter thickness control into the tube mill, which can carry through to the finished tube — without the conversion cost of a drawing operation.
It is the common choice when Type 1 surface or dimensional behavior is marginal for the application, but a drawn route (Type 5 or 6) would be over-buying.
Where Type 2 fits
Type 2 may offer a cleaner starting surface and more controlled dimensions than a hot-rolled as-welded route, while avoiding the conversion cost of drawn tubing. Actual capability remains producer- and size-dependent.
Typical evaluations include visible or coated components, furniture and fixture tubing, and mechanical parts with moderate fit requirements.
Questions for the supplier
Confirm weld treatment, surface expectations, dimensional capability, condition, and whether the intended bending, flattening, machining, coating, or cosmetic use requires additional controls.
Common specification mistakes
Assuming CREW equals a specific surface finish class; assuming cold-rolled strip guarantees drawn-tube concentricity; and leaving weld-bead condition unstated when the part slides over a mandrel, shaft, or fitting.
Sources and limitations
- ASTM A513/A513M — Standard Specification for Electric-Resistance-Welded Carbon and Alloy Steel Mechanical Tubing — ASTM International. Controlling specification for types, tolerances, and ordering requirements. Purchase the current edition for all normative values.
These sources inform the qualitative guidance on this page. This publication does not reproduce their text, tables, numerical settings, or acceptance criteria. Normative requirements come only from the purchased current edition of the governing standard and your supplier agreement.