Stainless Steel HF
UNS J92603
HF (J92603, ASTM A297/A743) is an 18-8 type austenitic heat-resistant casting grade with a composition similar to CF8, used for moderate-temperature oxidizing service.
Reference datasheet — HF 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 AC condition
HF tempers and conditions
HF is supplied in 3 conditions, soft to hard. AC 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 |
|---|---|---|---|---|---|---|
Solution Annealed | Choose when the casting sees aqueous/corrosive service or needs maximum ductility and the most homogeneous carbide-free matrix. | 285 | 585 | 45 | 155 HB | 2.2 % IACS |
ACDefault Spheroidize annealed | Standard supply condition for furnace and heat-treatment fixture castings that will operate hot; no post-cast heat treatment. | 310 | 620 | 38 | 165 HB | — |
Aged / Service-Exposed | Use these numbers for design checks on parts that have already spent long periods in the 600–900 °C range — strength rises, toughness collapses. | 380 | 655 | 18 | 11 HRC | 2.4 % IACS |
What is HF?
HF (J92603, ASTM A297/A743) is an 18-8 type austenitic heat-resistant casting grade with a composition similar to CF8, used for moderate-temperature oxidizing service. Typical values are 310 MPa yield, 620 MPa tensile, 38 % elongation and 165 HB (85 HRB), with a maximum service temperature of 870 °C in as-cast, solution-annealed or aged condition. It is more ductile and easier to weld than the high-chromium HE grade, but the 870 °C ceiling and work-hardening behaviour during machining are the practical limits; HE or HG-10MnN suit hotter or nickel-restricted duty. HF has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). HF has a yield strength of 310 MPa (45 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 63% of stainless steel grades. Elongation at break is 38% and the elastic modulus is 193 GPa (28 Msi).
What is HF used for?
- furnace trays
- grates
- heat-treatment fixtures
Advantages
- High service temperature — 870°C (1,598 °F), better than 83% of stainless steel grades
Limitations
- Limited formability — 10/100, worse than 95% of stainless steel grades
- Hard to polish — 50/100, worse than 93% of stainless steel grades
- Difficult to weld — 50/100, worse than 77% of stainless steel grades
HF properties
Typical room-temperature values for HF-AC; bars are the position among stainless steel grades.
Physical3
HF has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical13
HF has a yield strength of 310 MPa (45 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 63% of stainless steel grades. Elongation at break is 38% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
HF is rated for continuous service to 870°C (1,598 °F). It conducts heat at 14.2 W/m·K (8.2 BTU/hr·ft·°F), worse than 76% of stainless steel grades. Thermal expansion is 17.3 µm/m·K (9.61 µin/in·°F).
Electrical3
HF conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 71% of stainless steel grades.
Sustainability4
Producing a kilogram of HF takes about 53 MJ of energy and emits 4.5 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
HF's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability fair (50/100); formability not recommended (10/100).
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. HF is highlighted; hover a dot for its name, or open the interactive family chart.
Working with HF
Is HF easy to machine?
Work-hardening and carbide-loaded — use rigid setups, positive-rake carbide (C2/K20 or coated grades), 30–60 m/min, heavy positive feed to stay under the hardened skin, and flood coolant.
Can HF be welded?
Weldable with ER308/E308 or over-alloyed ER312 for as-cast repair; preheat 150–200 °C on heavy sections, limit interpass, and re-solution-anneal if aqueous corrosion service follows.
Can HF be formed, bent or molded?
Sand or investment cast only; good fluidity but high solidification shrinkage (~2.2 %) demands generous risering and chills at section changes.
HF 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 |
|---|---|---|
| Chigh carbon for creep strength; distinguishes HF from CF8 | 0.2 – 0.4 | 0.3 |
| Mn | ≤ 2 | 1.2 |
| Siaids fluidity and oxidation resistance | ≤ 2 | 1.3 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Cr | 19 – 23 | 21 |
| Ni | 9 – 12 | 10.5 |
| Moresidual only unless otherwise agreed | ≤ 0.5 | |
| Fe | balance |
What surface finishes work on HF?
Grit blast plus pickle/passivate (ASTM A967) for corrosion service, or pre-oxidize at 900 °C to form a protective Cr₂O₃ scale before furnace duty; no anodizing.
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 HF in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- J92603
How much does HF cost?
HF is a premium-cost stainless steel ($$$), cheaper than about 51% 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.
HF — frequently asked
What is HF used for?
HF is typically used for furnace trays, grates and heat-treatment fixtures. In short: cast CF8 for heat service; ductile 18-8 heat-resistant grade; weldable furnace casting.
What is the yield strength of HF?
HF has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 63% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is HF easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Work-hardening and carbide-loaded — use rigid setups, positive-rake carbide (C2/K20 or coated grades), 30–60 m/min, heavy positive feed to stay under the hardened skin, and flood coolant.
Can HF be welded?
With care — weldability is rated fair (50/100). Weldable with ER308/E308 or over-alloyed ER312 for as-cast repair; preheat 150–200 °C on heavy sections, limit interpass, and re-solution-anneal if aqueous corrosion service follows.
What surface finishes work on HF?
Grit blast plus pickle/passivate (ASTM A967) for corrosion service, or pre-oxidize at 900 °C to form a protective Cr₂O₃ scale before furnace duty; no anodizing.
Can HF be formed, bent or molded?
Sand or investment cast only; good fluidity but high solidification shrinkage (~2.2 %) demands generous risering and chills at section changes.
What is the maximum service temperature of HF?
HF is rated for continuous use to about 870°C (1,598 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between HF-AC and HF Aged?
AC is the default condition — standard supply condition for furnace and heat-treatment fixture castings that will operate hot; no post-cast heat treatment. Aged: use these numbers for design checks on parts that have already spent long periods in the 600–900 °C range — strength rises, toughness collapses. Yield strength is 310 MPa in AC versus 380 MPa in Aged.
How much does HF cost?
HF is a premium-cost stainless steel ($$$), cheaper than about 51% 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
- ASTM A297/A297M — Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant, for General Application — ASTM International (2019)
- ASTM A743/A743M — Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application — ASTM International (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Heat-Resistant Castings) — ASM International (1990)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM (1995)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
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.