Stainless Steel Haynes 556-SA (Solution Annealed)
Heat-treated state · default condition
UNS R30556 · ASTM B564/B435
Standard mill condition for sheet, plate and strip; best combination of ductility, weldability and high-temperature corrosion resistance.
Values for the SA condition
Other Haynes 556 tempers and conditions
Haynes 556 is listed in 4 conditions; see the grade overview at Haynes 556.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot Rolled + Solution Annealed | Heavy-section plate and forgings; slightly coarser grain and marginally lower strength than thin annealed sheet. | 390 | 790 | 50 | 10 HRC | 1.8 % IACS |
SADefaultThis page Solution Annealed | Standard mill condition for sheet, plate and strip; best combination of ductility, weldability and high-temperature corrosion resistance. | 410 | 815 | 48 | 200 HB | — |
As-welded deposit | Weld-metal / joint condition used for design of fabricated furnace and incinerator components; usually left as-welded without PWHT. | 450 | 770 | 33 | 210 HB | 1.8 % IACS |
Cold worked | Cold-drawn wire, tube or bar where higher room-temperature strength and straightness matter; ductility and high-temperature stability are reduced. | 750 | 1,000 | 18 | 32 HRC | 1.8 % IACS |
What is Haynes 556-SA?
Haynes 556-SA is Haynes 556 heat treated to SA — standard mill condition for sheet, plate and strip; best combination of ductility, weldability and high-temperature corrosion resistance. Haynes 556-SA has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 815 MPa (118 ksi) — stronger than 60% of stainless steel grades. Elongation at break is 48% and the elastic modulus is 205 GPa (29.7 Msi). Haynes 556-SA has a density of 8.23 g/cm³ (0.297 lb/in³), heavier than 100% of stainless steel grades. It melts at 1,320°C (2,408 °F).
Advantages
- High service temperature — 1,100°C (2,012 °F), better than 96% of stainless steel grades
- Ductile — tolerates forming and impact — 48%, better than 85% of stainless steel grades
- Good corrosion resistance — 78/100, better than 84% of stainless steel grades
Limitations
- High embodied carbon — 17 kg CO₂/kg, worse than 100% of stainless steel grades
- Difficult to machine — 20/100, worse than 98% of stainless steel grades
- Poor heat conductor — 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades
- Low electrical conductivity — 1.8 % IACS, worse than 87% of stainless steel grades
Haynes 556-SA properties
Typical room-temperature values for Haynes 556-SA; 11 are specific to this condition. Other listed values are Haynes 556 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
Haynes 556-SA has a density of 8.23 g/cm³ (0.297 lb/in³), heavier than 100% of stainless steel grades. It melts at 1,320°C (2,408 °F).
Mechanical13
Haynes 556-SA has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 815 MPa (118 ksi) — stronger than 60% of stainless steel grades. Elongation at break is 48% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal5
Haynes 556-SA is rated for continuous service to 1,100°C (2,012 °F). It conducts heat at 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades. Thermal expansion is 14.1 µm/m·K (7.83 µin/in·°F).
Electrical3
Haynes 556-SA conducts electricity at 1.8 % IACS, worse than 87% of stainless steel grades.
Chemical & Environmental2
Corrosion resistance is very good (78/100), better than 84% of stainless steel grades.
Sustainability3
Producing a kilogram of Haynes 556-SA takes about 240 MJ of energy and emits 17 kg of CO₂ — more than 100% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
Haynes 556-SA's machinability is poor (20/100, worse than 98% of stainless steel grades); weldability very good (72/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Haynes 556-SA
Is Haynes 556 easy to machine?
Machine like a solid-solution superalloy: rigid setup, positive rake carbide, low speed / heavy positive feed, flood coolant, avoid dwelling to prevent rapid work hardening.
Can Haynes 556 be welded?
Readily GTAW/GMAW/SMAW-welded with matching 556 filler; keep heat input low, use clean surfaces and no preheat/PWHT for normal sections.
Can Haynes 556 be formed, bent or molded?
Cold formable but springy and fast-work-hardening — allow extra power and intermediate solution anneals at 1175–1205 °C with rapid cooling; hot work 1180–1010 °C.
What surface finishes work on Haynes 556?
Grit blast or pickle to remove Cr-rich scale before service; not anodizable, and coatings are usually unnecessary since the alloy relies on its own protective oxide.
Haynes 556 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cr | 21 – 23 | 22 |
| Ni | 19 – 22.5 | 20 |
| Co | 16 – 21 | 18 |
| Mo | 2.5 – 4 | 3 |
| W | 2 – 3.5 | 2.5 |
| Ta | 0.3 – 1.25 | 0.6 |
| Mn | 0.5 – 2 | 1 |
| Si | 0.2 – 0.8 | 0.4 |
| Al | 0.1 – 0.5 | 0.2 |
| C | 0.05 – 0.15 | 0.1 |
| N | 0.1 – 0.3 | 0.2 |
| Larare-earth addition improving oxide scale adhesion | 0.01 – 0.1 | 0.02 |
| Zr | 0 – 0.1 | 0.02 |
| P | ≤ 0.04 | — |
| S | ≤ 0.02 | — |
| Febalance, nominally ~29 % | balance | — |
Haynes 556-SA — frequently asked
What is Haynes 556-SA used for?
Haynes 556-SA is typically used for waste incineration components, chemical process heaters, gas turbine hardware and industrial furnace fixtures. In short: multi-mode hot corrosion resistance; 1100 °C service ceiling; weldable with matching filler.
What is the yield strength of Haynes 556-SA?
Haynes 556-SA has a typical yield strength of 410 MPa (59.5 ksi) and a tensile strength of 815 MPa (118 ksi) — stronger than 60% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is Haynes 556-SA easy to machine?
Not especially — machinability is rated poor (20/100, worse than 98% of stainless steel grades). Machine like a solid-solution superalloy: rigid setup, positive rake carbide, low speed / heavy positive feed, flood coolant, avoid dwelling to prevent rapid work hardening.
Can Haynes 556-SA be welded?
Yes — weldability is rated very good (72/100). Readily GTAW/GMAW/SMAW-welded with matching 556 filler; keep heat input low, use clean surfaces and no preheat/PWHT for normal sections.
What surface finishes work on Haynes 556-SA?
Grit blast or pickle to remove Cr-rich scale before service; not anodizable, and coatings are usually unnecessary since the alloy relies on its own protective oxide.
Can Haynes 556-SA be formed, bent or molded?
Cold formable but springy and fast-work-hardening — allow extra power and intermediate solution anneals at 1175–1205 °C with rapid cooling; hot work 1180–1010 °C.
What is the maximum service temperature of Haynes 556-SA?
Haynes 556-SA is rated for continuous use to about 1,100°C (2,012 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Haynes 556-SA and Haynes 556-CW?
SA is the default condition — standard mill condition for sheet, plate and strip; best combination of ductility, weldability and high-temperature corrosion resistance. CW: cold-drawn wire, tube or bar where higher room-temperature strength and straightness matter; ductility and high-temperature stability are reduced. Yield strength is 410 MPa in SA versus 750 MPa in CW.
Sources
- HAYNES 556 alloy technical data — Haynes International (2020)
- ASTM B435 — UNS R30556 Sheet, Plate and Strip — ASTM (2019)
- ASTM B572 — UNS R30556 Rod — ASTM (2019)
- ASTM B622 / B626 — seamless and welded tube, UNS R30556 — ASTM (2019)
- ASM Handbook Vol.1 — Heat-Resistant Alloys — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.