Stainless Steel HD-F (As fabricated)
Temper · default condition
UNS J93005 · ASTM A297 Grade HD
Standard supply condition for all A297 HD castings; no heat treatment is required or normally applied.
Values for the F condition
Other HD tempers and conditions
HD is listed in 3 conditions; see the grade overview at HD.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed ~1040–1065 °C, rapid cool | Optional treatment used to dissolve grain-boundary carbides and re-solution sigma phase, giving the best available room-temperature ductility before machining or welding. | 320 | 560 | 18 | 180 HB | 2.1 % IACS |
FDefaultThis page As fabricated | Standard supply condition for all A297 HD castings; no heat treatment is required or normally applied. | 345 | 585 | 16 | 12 HRC | 2 % IACS |
Aged / service-exposed | Represents the embrittled condition after prolonged exposure in the 600–900 °C range; use these values for design checks on repair, handling and thermal-cycling loads. | 415 | 655 | 4 | 20 HRC | 2 % IACS |
What is HD-F?
HD-F is HD in the F temper — standard supply condition for all A297 HD castings; no heat treatment is required or normally applied. HD-F has a yield strength of 345 MPa (50 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 54% of stainless steel grades. Elongation at break is 16% and the elastic modulus is 195 GPa (28.3 Msi). HD-F has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Advantages
- High service temperature — 1,090°C (1,994 °F), better than 93% of stainless steel grades
- Low embodied carbon — 3.6 kg CO₂/kg, better than 83% of stainless steel grades
Limitations
- Limited formability — 5/100, worse than 99% of stainless steel grades
- Hard to polish — 45/100, worse than 96% of stainless steel grades
- Limited ductility — 16%, worse than 88% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- Difficult to weld — 35/100, worse than 86% of stainless steel grades
HD-F properties
Typical room-temperature values for HD-F; 21 are specific to this condition. Other listed values are HD reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
HD-F has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical15
HD-F has a yield strength of 345 MPa (50 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 54% of stainless steel grades. Elongation at break is 16% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal5
HD-F is rated for continuous service to 1,090°C (1,994 °F). It conducts heat at 19 W/m·K (11 BTU/hr·ft·°F), better than 73% of stainless steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
HD-F conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 58% of stainless steel grades.
Sustainability4
Producing a kilogram of HD-F takes about 50 MJ of energy and emits 3.6 kg of CO₂ — less than 80% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
HD-F's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability fair (35/100); formability not recommended (5/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with HD-F
Is HD easy to machine?
Machine with rigid setups, positive-rake carbide, low speed and heavy feed to cut below the work-hardened skin; abrasive carbides give short tool life, so grinding is often preferred for finish surfaces.
Can HD be welded?
Weldable with E/ER 312 (29-9) or matching HD filler; preheat 150–260 °C, keep interpass moderate and slow-cool, then optionally solution anneal — as-cast and aged material is crack-sensitive.
Can HD be formed, bent or molded?
Sand or investment cast only; good fluidity but design generous fillets and avoid restrained sections because of the low hot ductility and high shrinkage of high-Cr alloys.
What surface finishes work on HD?
Normally supplied shot-blasted as-cast; passivate or leave the self-forming Cr₂O₃ scale — no anodizing, and plating adheres poorly to the cast skin.
HD 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 |
|---|---|---|
| C0.50 % max per ASTM A297 | ≤ 0.5 | 0.4 |
| Mn | ≤ 1.5 | 1 |
| Sihigh Si aids scaling resistance | ≤ 2 | 1.5 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Cr | 26 – 30 | 28 |
| Ni | 4 – 7 | 5.5 |
| Moresidual, not intentionally added | ≤ 0.5 | — |
| Fe | balance | — |
HD-F — frequently asked
What is HD-F used for?
HD-F is typically used for radiant tube supports, furnace fixtures, heat treatment baskets and high-temperature process equipment. In short: stronger than Grade HC; 28Cr-5Ni heat-resisting casting; 1090 °C oxidizing service.
What is the yield strength of HD-F?
HD-F has a typical yield strength of 345 MPa (50 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 54% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is HD-F easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Machine with rigid setups, positive-rake carbide, low speed and heavy feed to cut below the work-hardened skin; abrasive carbides give short tool life, so grinding is often preferred for finish surfaces.
Can HD-F be welded?
With care — weldability is rated fair (35/100). Weldable with E/ER 312 (29-9) or matching HD filler; preheat 150–260 °C, keep interpass moderate and slow-cool, then optionally solution anneal — as-cast and aged material is crack-sensitive.
What surface finishes work on HD-F?
Normally supplied shot-blasted as-cast; passivate or leave the self-forming Cr₂O₃ scale — no anodizing, and plating adheres poorly to the cast skin.
Can HD-F be formed, bent or molded?
Sand or investment cast only; good fluidity but design generous fillets and avoid restrained sections because of the low hot ductility and high shrinkage of high-Cr alloys.
What is the maximum service temperature of HD-F?
HD-F is rated for continuous use to about 1,090°C (1,994 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between HD-F and HD Aged?
F is the default condition — standard supply condition for all A297 HD castings; no heat treatment is required or normally applied. Aged: represents the embrittled condition after prolonged exposure in the 600–900 °C range; use these values for design checks on repair, handling and thermal-cycling loads. Yield strength is 345 MPa in F versus 415 MPa in Aged.
Sources
- ASTM A297/A297M — Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant, for General Application — ASTM International (2019)
- High Alloy Data Sheets, Heat Series (Grade HD) — Steel Founders' Society of America (SFSA) (2004)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys (Heat-Resistant Castings) — ASM International (1990)
- ASM Handbook Vol. 13B: Corrosion — Materials — ASM International (2005)
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.