ASTM A500 Square and Rectangular Hollow Sections: A Buyer's Guide
ASTM A500 purchasing guide
An ASTM A500 hollow-section order should identify the current standard edition, required grade, outside dimensions, design wall thickness, length, and any supplementary dimensional, marking, document, or inspection requirements. The designation alone is not a complete purchase specification. Buyers also need to distinguish square hollow section (SHS) from rectangular hollow section (RHS), define how dimensions will be verified, and state what records must accompany the shipment.
What an A500 RFQ must resolve
- Product form: SHS or RHS, with outside dimensions written in a consistent order.
- Standard edition and grade selected by the project authority.
- Design wall thickness, ordered length, quantity, and applicable tolerances.
- Corner, straightness, and twist requirements tied to the governing documents.
- Marking, material test report, and inspection evidence required for acceptance.
Translate SHS and RHS terminology into order fields
SHS has equal outside side dimensions; RHS has unequal outside width and height. Those labels help classify the section, but the purchase line should still state both outside dimensions and the design wall thickness. Keep the dimension order consistent between the RFQ, quotation, drawing, purchase order, packing list, and inspection record so that width and height are not reversed.
Minimum product identity
- ASTM A500 and the required edition
- Grade stated exactly as required
- Square or rectangular form
- Outside dimensions and design wall
- Ordered length and quantity
Do not leave implicit
- Which dimension is width or height
- Whether nominal wording is acceptable
- Project-specific tolerances
- Special end, surface, or packaging needs
- Required inspection and release records
Control the standard edition and grade
ASTM A500 covers cold-formed welded and seamless carbon steel structural tubing in round and shaped forms, but this guide addresses square and rectangular sections. Grade designation, mechanical requirements, permissible variation, tests, marking, and other details depend on the applicable edition and the ordered product. The purchaser should use the project specification and the current standard text instead of copying values from an undated chart.
Specify outside dimensions, wall and corner geometry
Write an SHS size as outside side × outside side × design wall thickness. Write an RHS size as outside width × outside height × design wall thickness, and define the orientation when it matters to fabrication. Corner geometry is part of the formed product rather than a sharp mathematical intersection. If connections, inserts, cladding, clearances, or fit-up depend on the corner region, place the functional requirement on the drawing and confirm it against the applicable standard and supplier data.
| Order field | Buyer input | Acceptance reference |
|---|---|---|
| Section form | SHS or RHS | PO and drawing |
| Outside dimensions | Side × side or width × height | ASTM edition and project tolerance |
| Wall | Design wall thickness | Applicable standard provisions |
| Corner-dependent fit | Functional clearance or detail | Approved fabrication drawing |
| Length | Fixed or agreed ordered length | PO and inspection plan |
Keep application context separate from product acceptance
Square and rectangular hollow sections are used in frames, columns, trusses, equipment supports, gates, and fabricated assemblies because their closed geometry can support practical connections and clean profiles. That application context does not select a grade, wall, section size, or connection detail. A qualified design authority must establish loads, member selection, connection design, corrosion protection, fire requirements, and any project-specific acceptance criteria.
Plan straightness, twist and visual checks
Inspection should compare the delivered sections with the ordered form, size, wall, length, and applicable permissible variations. Straightness and twist affect fit-up, alignment, and fabrication, but the measurement method, reference length, instrument, sampling plan, and acceptance limit must come from the governing edition or project documents. Visual review should also record end condition, handling damage, surface condition, and identification without converting appearance into a grade claim.
- 1Reconcile documents. Match the PO, packing list, material test report, and bundle identification before measuring.
- 2Confirm the sample plan. Record heat, lot, bundle, and piece selection as required by the inspection plan.
- 3Verify dimensions. Use calibrated equipment and the method required by the applicable standard or project procedure.
- 4Record straightness and twist. State the reference length, setup, observations, and actual results.
- 5Close discrepancies. Quarantine or document nonconforming items under the agreed disposition process.
Build the inspection and document package
The evidence package should let the buyer trace what was ordered, supplied, inspected, and released. Request the material test report and marking information needed by the contract. For dimensional checks, preserve the instrument identification, calibration status, method, sample identity, results, and inspector sign-off. Any additional test or third-party inspection requirement should be written into the RFQ and PO before production.
A500 buyer checklist
- Current ASTM A500 edition and exact grade
- SHS/RHS designation and dimension order
- Outside dimensions, design wall, length, quantity
- Project-specific corner or fit-up requirements
- Straightness and twist verification method
- Surface, end, marking, and bundle requirements
- Material test report and traceability fields
- Inspection scope, sampling, reports, and release point
ASTM A500 ordering FAQ
Is “ASTM A500 square tube” a complete description?
No. Add the standard edition, grade, outside side dimensions, design wall thickness, ordered length, quantity, and required documents or supplementary requirements.
Can a buyer identify the A500 grade from a photograph?
No. Grade and compliance require the applicable records and test evidence, including the material test report and purchase-order traceability.
Why should RHS dimension order be controlled?
Consistent width × height notation prevents orientation errors across drawings, quotations, purchase orders, fabrication instructions, and inspection records.
Should an RFQ copy tolerance values from an online size chart?
Not as the acceptance basis. Use the applicable ASTM A500 edition and project documents, because undated secondary charts may be incomplete or unsuitable for the order.
Ordering conclusion
A reliable A500 SHS/RHS order connects product identity, dimensions, project requirements, traceability, and an agreed inspection method. Treat the standard designation as the start of the specification, then use the governing edition, drawings, RFQ, PO, and material records to define and verify acceptance.
