Procurement standard brief
ASTM A479/A479M: Stainless Steel Bars and Shapes for Boilers and Pressure Vessels
Use ASTM A479/A479M when the pressure-equipment material specification calls for covered stainless bars and shapes, then coordinate the grade, product condition, size, machining allowance, tests, traceability, and documents with the governing construction code and component drawing. The A479 designation does not design a shaft, stem, bolting item, or vessel component, and it does not establish allowable stress or finished-part acceptance. Keep its role distinct from general A276 bar procurement.
- Use this guide for
- Pressure-equipment material selection and bar procurement
- Relevant to
- Pressure-vessel, boiler, valve, EPC, machine-shop, and quality buyers
Contract responsibility
Scope and Explicit Exclusions
What this material standard controls
Pressure-equipment bar material
A479/A479M provides a stainless bar and shape material route for boiler and pressure-vessel construction within its scope. The order selects the covered grade, section, dimensions, heat-treatment condition, and required options.
Properties and heat treatment
The specification coordinates chemistry, mechanical requirements, heat treatment, testing, and certification for the ordered product. Size and condition can affect requirements, so the exact line item and contract edition matter.
Material release evidence
The material standard establishes base examination and marking responsibilities. Project requirements for PMI, UT, hardness mapping, witness, source inspection, marking transfer, and component traceability must be added before manufacture.
What it does not control alone
- A479/A479M does not establish the pressure component design, allowable stress, design life, corrosion allowance, load case, thread or seal geometry, welding qualification, or completed-equipment acceptance.
- It does not define every finished component dimension or machining requirement; the approved drawing must state stock allowance, datum, heat treatment after machining, surface, and inspection.
- It is not interchangeable with ASTM A276/A276M merely because both specifications list a similar stainless grade or bar form.
Specification stack
Related Standards and Responsibility Chain
| Document | Procurement role | Boundary |
|---|---|---|
| ASTM A479/A479M | Defines the pressure-equipment stainless bar and shape material basis, grade requirements, condition, tests, marking, and certification. | The purchase order must select the grade, form, size, condition, and supplementary controls from the contract edition. |
| Governing boiler or pressure-vessel code | Controls permitted material use, design rules, allowable values, fabrication, examination, pressure testing, documentation, and certification of the equipment. | A479 material conformity is evidence for one component input, not completed-code acceptance. |
| ASTM A484/A484M where invoked | Commonly coordinates general bar dimensional, tolerance, and delivery provisions. | Special straightness, diameter, corner, length, surface, or conditioning restrictions still need explicit purchase requirements. |
| Component drawing and quality plan | Define raw-stock allowance, finished geometry, machining, heat treatment, NDE, marking transfer, serialization, and release hold points. | The mill certificate cannot certify machining quality or the final pressure-retaining component. |
Line-item completeness
How to Order to This Standard
| Field | What to state | Why it matters |
|---|---|---|
| Material and code basis | Name ASTM A479/A479M revision, governing construction code and edition, component specification, and project supplements. | Links material procurement to the actual pressure-equipment route without merging their responsibilities. |
| Grade and condition | State grade or UNS, required heat treatment, size-dependent condition, and any chemistry, hardness, ferrite, or mechanical restrictions. | Pressure-component acceptance depends on the ordered grade and condition, not a trade name alone. |
| Product form | Identify round, flat, square, shape, or drawing section and whether hot-finished, cold-finished, peeled, turned, ground, or otherwise processed. | Form and route affect properties, tolerances, surface, examination, and available machining stock. |
| Raw dimensions | Give stock size, length, dimensional tolerance, straightness, end allowance, forging or machining stock, and units. | The machine shop needs enough sound material to achieve the approved finished drawing. |
| Surface and repair | Define surface route, defect and conditioning limits, weld-repair prohibition or procedure, roughness, and protected areas. | Surface removal and repair can affect identity, dimensions, examination, and component acceptance. |
| Tests and examination | List required mechanical tests, hardness, PMI, UT or other NDE, sampling, witness, acceptance criteria, and report format. | Supplementary examination must be planned around the original bar and component route. |
| Traceability | State heat, bar, cut-piece, and component marking transfer; material map; certificate indexing; remnant control; and serialization point. | Pressure-equipment dossiers need continuity after sawing and machining. |
| Quantity and logistics | Give pieces, mass, cut plan, packing, rust and damage protection, source-inspection release, destination, and requested schedule. | Commercial comparison requires the same yield, inspection, and release assumptions. |
Copy structure, replace values
Purchase Description Example
Pre-award review
Ordering Mistakes and Corrections
| Mistake | Likely consequence | Correction |
|---|---|---|
| Changing an A479 line item to A276 because the grade matches. | The material can follow a different specification and certification route from the one invoked by the pressure-equipment design and quality dossier. | Obtain engineering and quality review of the exact specification, edition, grade, condition, test, and documentation differences before any change. |
| Buying finished-diameter bar with no machining stock. | Mill tolerance, surface conditioning, straightness, chucking, and defect removal can prevent the machine shop from achieving the drawing. | Set raw diameter, length allowance, straightness, surface route, and clean-up stock through a documented machining review. |
| Assuming the A479 certificate releases the machined component. | Machining, heat treatment, threads, seals, NDE, marking, dimensions, and damage after material release remain unverified. | Maintain separate material receipt, in-process, final-dimensional, NDE, and component-release records tied by traceability. |
| Leaving code edition and component class out of the RFQ. | Suppliers cannot identify the adopted requirements, witness points, or supplementary tests, and quotations may not be comparable. | State the construction-code basis, component specification, drawing revision, quality plan, and material-standard revision in the inquiry. |
Continue the specification
Products, Grades, Applications, and Adjacent Standards
Grade datasheets
Adjacent standards
Application briefs
Surface guidance
Buyer questions
Frequently Asked Questions
How is ASTM A479 different from ASTM A276?
A479/A479M is a bar and shape material specification used for boiler and pressure-vessel construction when invoked. A276/A276M is a general bar and shape specification. Similar grades do not remove differences in contract role, testing, certification, and project approval.
Does ASTM A479 define the finished valve stem or shaft?
No. It defines the ordered bar or shape material. The component drawing and quality plan must define raw allowance, finished dimensions, machining, heat treatment, surface, NDE, marking transfer, serialization, and final release.
What traceability should an A479 RFQ request?
State the certificate, heat and original-bar identity, cut map, marking transfer to blanks, remnant control, component serialization point, and document index. The exact level should follow the governing code and project quality plan.
Published by Tsingshan (Shandong) Iron & Steel Co., Ltd..Sources, update policy and technical limitations.
Quotation package
What to Include in the RFQ
- ASTM A479/A479M and construction-code contract editions
- Component specification, drawing revision, and service or material basis
- Grade, UNS, heat treatment, and chemistry or hardness controls
- Section, raw size, tolerance, straightness, length, and machining allowance
- Hot- or cold-finished, peeled, turned, ground, or other surface route
- Mechanical tests, hardness, PMI, UT or NDE, witness, and acceptance scope
- Certificate, heat-to-component traceability, marking transfer, and dossier index
- Quantity, cut plan, packing, destination, release points, and requested schedule
Quote request
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