Overview
ASTM B446-26 covers hot- and cold-worked rod and bar in UNS N06625, N06219 and N06650. N06625 includes annealed, solution-annealed and solution-annealed/cold-worked strength conditions. A complete order states alloy, grade, working route, section, length, straightness, surface, tests and end-use qualification.
Designation and acceptance
B446 long products are distinct from B443 flat products and from nickel-alloy forgings. N06625 Grade 1 is annealed, Grade 2 solution annealed and Grade 3 solution annealed plus cold worked for higher strength; N06219 and N06650 are solution annealed. Subsequent hot work or reannealing can change properties, while cold-work strength can vary with section and processing history.
Members and selection
| Designation | Selection context |
|---|---|
| N06625 Grade 1 | Annealed rod/bar for the qualified corrosion and temperature range. |
| N06625 Grade 2 | Solution-annealed rod/bar where elevated-temperature creep/rupture basis is required. |
| N06625 Grade 3 | Solution-annealed and cold-worked product where higher strength is needed and section capability is verified. |
| N06219 / N06650 | Solution-annealed rod and bar under the exact alloy-specific requirements. |
Comparison framework
| Criterion | Decision context |
|---|---|
| Hot vs cold worked | Working route affects surface, residual stress, section capability and properties. |
| Grade 1/2/3 | Heat-treatment and cold-work conditions serve different strength/temperature intents. |
| Rod/bar vs forging | B446 long-product stock does not certify a final forging or forging stock under another specification. |
| Alloy trade name | A commercial name cannot replace UNS, B446 grade, condition and dimensions. |
Performance
- Acceptance under ASTM B446 Nickel Bars depends on the exact alloy or grade, delivered condition, product geometry and specified test basis rather than the standard number alone.
- Residual stress, surface tearing, grain condition and unplanned reheating can change performance after compliant delivery.
- Service suitability remains an engineering decision: higher strength from cold work is not a universal substitute for solution-annealed elevated-temperature service.
Orderable product scope
- Hot-worked nickel-alloy rod and bar in round or permitted section.
- Cold-worked rod or bar where dimensional finish or Grade 3 strength is required.
- Cut-length machining stock with defined straightness, surface and end condition.
Processing
- Use low-contamination cutting and machining practices with controlled heat and tool condition.
- Qualify welding or hot forming because reheating can change cold-worked or heat-treated properties.
- Preserve heat and processing-lot identity through cutting and component manufacture.
Applications
- Valve, fastener, shaft and machined corrosion-resistant component stock.
- High-temperature or chemical-process long products using the correct B446 grade condition.
- Cold-work strengthened N06625 components where design and fabrication preserve the qualified condition.
Selection
- Confirm that ASTM B446 Nickel Bars actually covers the required product form and manufacturing route before comparing grades or quotations.
- Select alloy or grade and delivered condition from service, fabrication, section size and required property evidence; do not infer condition from a trade name.
- Require a written technical comparison and responsible-engineer approval before substituting another standard, alloy, condition or product route.
Procurement
- State ASTM B446-26, exact UNS alloy, Grade 1/2/3 where applicable and hot- or cold-worked route.
- State diameter/section, length, quantity, straightness, tolerances, end and surface condition.
- Define chemistry, tensile/hardness, condition verification and supplementary examination or corrosion testing.
- Require inspection report, heat and processing-lot traceability, marking, end protection and low-contamination packing.