Overview
ASTM A513/A513M-25 covers electric-resistance-welded carbon and alloy steel mechanical tubing made from hot- or cold-rolled steel in round and shaped sections. Purchasing depends on grade, Type 1–6 processing route, thermal condition, geometry, dimensional precision, surface and end-use fabrication tests.
Designation and acceptance
A513 identifies mechanical tubing whose type records feedstock and finishing route: as-welded hot- or cold-rolled products, sink-drawn variants, drawn-over-mandrel tubing and special smooth-inside-diameter tubing. Type is not a strength grade, and grade is not a dimensional finish; both must be stated with thermal condition, shape, size and acceptance tests.
Members and selection
| Designation | Selection context |
|---|---|
| Type 1a / 1b | As-welded hot-rolled feedstock with mill-scale or pickled/oiled surface distinctions. |
| Type 2 | As-welded cold-rolled feedstock for improved surface and dimensional expectations. |
| Types 3 / 4 | Sink-drawn routes based on hot- or cold-rolled input; confirm sizing and finish. |
| Types 5 / 6 | DOM or special smooth-ID routes for tighter mechanical-component requirements. |
Comparison framework
| Criterion | Decision context |
|---|---|
| A513 vs A500 | Mechanical type and finish do not create structural design qualification. |
| As-welded vs DOM | Drawing changes tolerances, surface, residual stress, cost and fabrication response. |
| Grade vs type | Grade addresses material identity while type addresses manufacturing route. |
| Nominal vs minimum wall | The drawing and order must state the dimensional basis used for acceptance. |
Performance
- Acceptance under ASTM A513 Mechanical Tubing depends on the ordered product branch, delivered condition, geometry and specified test basis rather than the standard number alone.
- Seam condition, draw history and thermal condition can change forming, machining and fatigue response.
- Service suitability remains an engineering decision: tight dimensions or a DOM label do not prove structural, pressure or safety-component qualification.
Orderable product scope
- Round ERW mechanical tube in straight cut lengths.
- Square, rectangular and special-shape mechanical tubing.
- DOM and smooth-ID tube for machined, sleeved or telescoping components.
Processing
- Account for weld seam, residual stress and thermal condition during bending, flaring or machining.
- Specify deburring, end finishing and cleanliness where tubes become precision assemblies.
- Qualify plating, painting or welding on the actual surface and rust-preventive oil condition.
Applications
- Automotive, appliance and machinery components.
- Bushings, rollers, shafts, sleeves and telescoping assemblies.
- Furniture and fabricated frames where a structural building specification is not required.
Selection
- Confirm that ASTM A513 Mechanical Tubing covers the required product form and manufacturing or coating route before comparing quotations.
- Select the grade, alloy, temper, coating or delivered condition from service, fabrication and the required acceptance evidence; never infer it from a trade name.
- Require a written technical comparison and responsible-engineer approval before substituting another standard, product route or condition.
Procurement
- State ASTM A513/A513M-25, grade, Type 1–6 and required thermal condition.
- State shape, OD or outside dimensions, wall basis, length, quantity and tolerance class.
- Define surface, seam position/removal, ID quality, straightness, ends and fabrication tests.
- Require inspection report, lot identity, rust protection, separators and damage-resistant packing.