Stainless Steel Haynes 556
UNS R30556 · ASTM B564/B435
Haynes 556 is an Fe-Ni-Co-Cr multiphase solid-solution alloy (UNS R30556, ASTM B564/B435) engineered for resistance to oxidizing, carburizing and sulfidizing high-temperature environments while retaining useful strength.
Reference datasheet — Haynes 556 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the SA condition
Haynes 556 tempers and conditions
Haynes 556 is supplied in 4 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
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 |
SADefault 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 |
Supply forms, finishes and certifications
Ways Haynes 556 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
SA-BAR | Solution Annealed bar / rod | Supply form |
What is Haynes 556?
Haynes 556 is an Fe-Ni-Co-Cr multiphase solid-solution alloy (UNS R30556, ASTM B564/B435) engineered for resistance to oxidizing, carburizing and sulfidizing high-temperature environments while retaining useful strength. Engineers specify it as solution-annealed and hot-rolled sheet, plate, bar and forgings for service to 1100 °C, where it provides 410 MPa yield, 815 MPa tensile, 48 % elongation and about 200 HB. The main penalties are cost and cycle time: machinability is rated 20 and the alloy work-hardens rapidly, so lower-alloy heat-resistant grades are preferred where multi-mode hot corrosion is not present. Haynes 556 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). Haynes 556 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).
What is Haynes 556 used for?
- waste incineration components
- chemical process heaters
- gas turbine hardware
- industrial furnace fixtures
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 properties
Typical room-temperature values for Haynes 556-SA; bars are the position among stainless steel grades.
Physical3
Haynes 556 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 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 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 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 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'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. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. Haynes 556 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Haynes 556
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.
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 |
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.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel Haynes 556 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R30556
- ASTM
- B564/B435
- Also called
- Haynes556
How much does Haynes 556 cost?
Haynes 556 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Haynes 556 — frequently asked
What is Haynes 556 used for?
Haynes 556 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?
Haynes 556 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 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 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?
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 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?
Haynes 556 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.
How much does Haynes 556 cost?
Haynes 556 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.