Stainless Steel RA85H
UNS S30615
RA85H (UNS S30615) is a high-silicon modification of Type 310 austenitic stainless with strong resistance to carburization and thermal cycling at service temperatures up to about 1095 °C.
Reference datasheet — RA85H 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 ANN condition
RA85H tempers and conditions
RA85H is supplied in 3 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot Finished / Hot Rolled Annealed bar | Large-diameter bar and forging stock for grate bars, rolls and heavy fixtures. | 340 | 650 | 44 | 185 HB | 1.7 % IACS |
ANNDefault Annealed | Standard stocked condition for plate, sheet, bar and pipe; maximum ductility and best carburization/oxidation resistance. | 345 | 655 | 45 | 180 HB | 1.7 % IACS |
Cold drawn | Choose for straight, close-tolerance bar stock (fixture pins, studs) where higher room-temperature strength is useful. | 550 | 760 | 25 | 20 HRC | 1.7 % IACS |
Supply forms, finishes and certifications
Ways RA85H is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
WELD-TUBE | Welded tube/pipe, annealed | Supply form |
CRA-2B | Cold Rolled, Annealed sheet | Surface finish |
HRAP | Hot Rolled, Annealed & Pickled plate | Surface finish |
What is RA85H?
RA85H (UNS S30615) is a high-silicon modification of Type 310 austenitic stainless with strong resistance to carburization and thermal cycling at service temperatures up to about 1095 °C. Annealed material provides roughly 345 MPa yield, 655 MPa tensile, 45 % elongation and 180 HB (88 HRB), and is supplied as annealed plate, hot-rolled annealed and pickled, cold-rolled 2B sheet, cold-drawn bar and welded tube. The silicon content makes it abrasive to machine and there is no matching weld filler, so high-nickel consumables are required; RA330-type or 253 MA are the usual alternatives when weld filler matching or higher creep strength matters. RA85H has a density of 7.72 g/cm³ (0.279 lb/in³), lighter than 72% of stainless steel grades. It melts at 1,350°C (2,462 °F). RA85H has a yield strength of 345 MPa (50 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 54% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
What is RA85H used for?
- heat-treat baskets and fixtures
- radiant tubes
- kiln rollers
Advantages
- High service temperature — 1,095°C (2,003 °F), better than 94% of stainless steel grades
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 86% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Low electrical conductivity — 1.7 % IACS, worse than 93% 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
- Hard to polish — 60/100, worse than 80% of stainless steel grades
RA85H properties
Typical room-temperature values for RA85H-ANN; bars are the position among stainless steel grades.
Physical3
RA85H has a density of 7.72 g/cm³ (0.279 lb/in³), lighter than 72% of stainless steel grades. It melts at 1,350°C (2,462 °F).
Mechanical16
RA85H has a yield strength of 345 MPa (50 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 54% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal4
RA85H is rated for continuous service to 1,095°C (2,003 °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 15.6 µm/m·K (8.67 µin/in·°F).
Electrical3
RA85H conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of RA85H takes about 58 MJ of energy and emits 5.2 kg of CO₂ — more than 66% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
RA85H's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability good (55/100); formability good (55/100).
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. RA85H is highlighted; hover a dot for its name, or open the interactive family chart.
Working with RA85H
Is RA85H easy to machine?
Machines like a tough, work-hardening 310 but harder on tools due to silicon — rigid setup, sharp positive-rake carbide, heavy positive feed, low-to-moderate SFM and flood coolant; never dwell or rub.
Can RA85H be welded?
GTAW/GMAW/SMAW with high-nickel filler (RA330-04, ERNiCr-3 or similar) — no matching filler; keep heat input and interpass temperature low, no preheat needed, post-weld anneal for maximum service ductility.
Can RA85H be formed, bent or molded?
Cold forms and rolls readily in annealed sheet but work hardens fast — allow extra power and interstage annealing at ~1120–1175 °C; hot work 1150–1200 °C and never finish below ~950 °C.
RA85H 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 |
|---|---|---|
| Ccarbon kept high for creep strength | 0.16 – 0.24 | 0.2 |
| Sikey addition for carburization/oxidation resistance | 3.2 – 4 | 3.6 |
| Mn | ≤ 2 | 1 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cr | 17 – 19.5 | 18.5 |
| Ni | 13.5 – 16 | 14.5 |
| Alco-forms protective Al/Si oxide | 0.8 – 1.5 | 1 |
| Fe | balance |
What surface finishes work on RA85H?
Pickle/passivate after hot work or welding to restore the Cr/Si oxide; a pre-oxidation soak in air at 1000–1100 °C builds the protective scale before service. Not anodizable; paint only for cold sections.
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 RA85H in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S30615
How much does RA85H cost?
RA85H 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.
RA85H — frequently asked
What is RA85H used for?
RA85H is typically used for heat-treat baskets and fixtures, radiant tubes and kiln rollers. In short: carburization-resistant 310 variant; service to 1095 °C; needs nickel-base filler.
What is the yield strength of RA85H?
RA85H has a typical yield strength of 345 MPa (50 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 54% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is RA85H easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Machines like a tough, work-hardening 310 but harder on tools due to silicon — rigid setup, sharp positive-rake carbide, heavy positive feed, low-to-moderate SFM and flood coolant; never dwell or rub.
Can RA85H be welded?
Yes — weldability is rated good (55/100). GTAW/GMAW/SMAW with high-nickel filler (RA330-04, ERNiCr-3 or similar) — no matching filler; keep heat input and interpass temperature low, no preheat needed, post-weld anneal for maximum service ductility.
What surface finishes work on RA85H?
Pickle/passivate after hot work or welding to restore the Cr/Si oxide; a pre-oxidation soak in air at 1000–1100 °C builds the protective scale before service. Not anodizable; paint only for cold sections.
Can RA85H be formed, bent or molded?
Cold forms and rolls readily in annealed sheet but work hardens fast — allow extra power and interstage annealing at ~1120–1175 °C; hot work 1150–1200 °C and never finish below ~950 °C.
What is the maximum service temperature of RA85H?
RA85H is rated for continuous use to about 1,095°C (2,003 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between RA85H-ANN and RA85H-CD?
ANN is the default condition — standard stocked condition for plate, sheet, bar and pipe; maximum ductility and best carburization/oxidation resistance. CD: choose for straight, close-tolerance bar stock (fixture pins, studs) where higher room-temperature strength is useful. Yield strength is 345 MPa in ANN versus 550 MPa in CD.
How much does RA85H cost?
RA85H 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
- RA 85H Heat Resistant Alloy Data Sheet — Rolled Alloys (2022)
- ASTM A167 / A240 / A479 supplementary listings for UNS S30615 — ASTM International (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Specialty Handbook: Heat-Resistant Materials — ASM International (1997)
- SAE/ASTM Metals & Alloys in the Unified Numbering System (UNS S30615) — SAE International (2017)
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.