ASTM A513 Type 1

Type 1 is the as-welded ERW route made from hot-rolled steel strip, and the standard splits it in two: Type 1a is made from hot-rolled strip carrying mill scale, while Type 1b is made from hot-rolled strip that has been pickled and oiled, giving a scale-free surface. Both are generally the most economical A513 routes and fit applications where the as-welded surface and baseline dimensional behavior are acceptable — typically fabricated frames, supports, and welded assemblies rather than precision-machined components.

In shop language, Type 1 is what most people mean by HREW. On a purchase order, write “ASTM A513 Type 1a” or “Type 1b” rather than the nickname — the letter decides whether the tube arrives with or without mill scale.

Hot-rolled strip carries the dimensional character of hot rolling into the tube mill, and — for Type 1a — its mill scale as well. Type 1b starts from pickled-and-oiled strip, so the scale has been chemically removed before forming. Forming and welding do not change these surface conditions; they define the as-welded product. Where appearance, coating adhesion, or tight fits matter, specify Type 1b, discuss surface preparation explicitly, or evaluate Type 2 or a drawn route instead.

Type 1 can be economical where the application accepts an as-welded route and does not require the tighter surface and dimensional outcomes associated with subsequent drawing.

• Frames, supports, and fabricated mechanical components
• Applications where downstream welding or forming dominates
• Projects with clearly negotiated dimensional requirements

Do not expect cold-rolled surface quality, drawn-tube concentricity, or guaranteed machining allowances from a Type 1 order. If the part drawing implies any of these, either add explicit negotiated requirements or move up the process ladder.

State Type 1 explicitly. Define shape, outside dimensions, wall, length, condition, tolerances, end finish, testing, and certification rather than relying on an informal HREW label.

Confirm whether weld flash (inside bead) condition matters for your application — flash-in, flash controlled, or flash removed are different products downstream of the same mill.