Stainless Steel 446 · finish state
Stainless Steel 446 Hot Rolled
Properties of the Hot Rolled condition, compared with the other 446 tempers.
Pick for heavy plate and hot-finished bar where a mill anneal is not required before further hot working.
What is 446 Hot Rolled?
446 Hot Rolled is 446 supplied in the Hot Rolled condition — pick for heavy plate and hot-finished bar where a mill anneal is not required before further hot working. 446 Hot Rolled has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 570 MPa (82.7 ksi) — stronger than 52% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi). 446 Hot Rolled has a density of 7.5 g/cm³ (0.271 lb/in³), lighter than 99% of stainless steel grades. It melts at 1,425°C (2,597 °F). Annealed is the default condition FabDigit quotes; Hot Rolled is available on request or by drawing note.
Advantages
- High service temperature — 1,095°C (2,003 °F), better than 94% of stainless steel grades
- Easy to machine — 45/100, better than 84% of stainless steel grades
- High electrical conductivity — 2.6 % IACS, better than 77% of stainless steel grades
- Conducts heat well — 20.9 W/m·K (12.1 BTU/hr·ft·°F), better than 76% of stainless steel grades
Limitations
- Difficult to weld — 30/100, worse than 89% of stainless steel grades
- Limited ductility — 20%, worse than 79% of stainless steel grades
446 Hot Rolled properties
Typical room-temperature values for 446 Hot Rolled — 8 properties are specific to this condition; the rest are grade-level values shared by every 446 temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
446 Hot Rolled has a density of 7.5 g/cm³ (0.271 lb/in³), lighter than 99% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical14
446 Hot Rolled has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 570 MPa (82.7 ksi) — stronger than 52% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
446 Hot Rolled is rated for continuous service to 1,095°C (2,003 °F). It conducts heat at 20.9 W/m·K (12.1 BTU/hr·ft·°F), better than 76% of stainless steel grades. Thermal expansion is 10.4 µm/m·K (5.78 µin/in·°F).
Electrical3
446 Hot Rolled conducts electricity at 2.6 % IACS, better than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 53% of stainless steel grades.
Sustainability4
Producing a kilogram of 446 Hot Rolled takes about 55 MJ of energy and emits 5 kg of CO₂ — less than 51% of stainless steel grades. Typical recycled content is 50%.
Manufacturability7
446 Hot Rolled's machinability is fair (45/100, better than 84% of stainless steel grades); weldability poor (30/100); formability poor (32/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 446 tempers and conditions
446 is also supplied in 2 other conditions. The full side-by-side table is on the 446 overview.
- AnnealedDefaultStandard stocked condition for all heat-resisting fabrication; anneal 760–830 °C and cool rapidly through 550–400 °C to avoid embrittlement.350 MPa yield · 180 HB
- Cold DrawnChoose cold-drawn bar for tighter tolerance, better surface and higher strength where ductility and toughness are not critical.480 MPa yield · 210 HB
- Hot RolledPick for heavy plate and hot-finished bar where a mill anneal is not required before further hot working.380 MPa yield · 190 HB
Working with 446 Hot Rolled
Is 446 easy to machine?
Machines like a soft ferritic stainless — rigid setup, sharp positive-rake carbide, heavy feed and flood coolant to break the gummy chip; rating ≈ 50 % of AISI 1212.
Can 446 be welded?
Weldable by GTAW/GMAW but HAZ grain coarsening embrittles the joint; use low heat input, no preheat above ~200 °C, 309/310 or matching high-Cr filler, and post-weld anneal at ~790 °C with fast cooling where possible.
Can 446 be formed, bent or molded?
Only fair cold formability — generous bend radii, forming above ~150–250 °C helps; hot work at 900–1150 °C and avoid slow cooling through 550–400 °C to prevent 475 °C embrittlement.
What surface finishes work on 446?
Pickle and passivate after hot work or welding; polishes to a bright ferritic finish, no anodising — service oxide scale is the intended protective layer.
446 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 |
|---|---|---|
| CASTM A176/A240 Type 446 | ≤ 0.2 | 0.1 |
| Cr | 23 – 27 | 25 |
| Mn | ≤ 1.5 | — |
| Si | ≤ 1 | — |
| Niresidual limit in most product specs | ≤ 0.75 | — |
| N | ≤ 0.25 | — |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
446 Hot Rolled — frequently asked
What is 446 Hot Rolled used for?
446 Hot Rolled is typically used for furnace parts and linings, exhaust and flue ducts, radiant tubes, burner nozzles and heads, heat treatment fixtures and baskets and sulfur-bearing flue gas ductwork. In short: heat-resistant ferritic stainless.
What is the yield strength of 446 Hot Rolled?
446 Hot Rolled has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 570 MPa (82.7 ksi) — stronger than 52% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is 446 Hot Rolled easy to machine?
Reasonably — machinability is rated fair (45/100, better than 84% of stainless steel grades). Machines like a soft ferritic stainless — rigid setup, sharp positive-rake carbide, heavy feed and flood coolant to break the gummy chip; rating ≈ 50 % of AISI 1212.
Can 446 Hot Rolled be welded?
Not readily — weldability is rated poor (30/100). Weldable by GTAW/GMAW but HAZ grain coarsening embrittles the joint; use low heat input, no preheat above ~200 °C, 309/310 or matching high-Cr filler, and post-weld anneal at ~790 °C with fast cooling where possible.
What surface finishes work on 446 Hot Rolled?
Pickle and passivate after hot work or welding; polishes to a bright ferritic finish, no anodising — service oxide scale is the intended protective layer.
Can 446 Hot Rolled be formed, bent or molded?
Only fair cold formability — generous bend radii, forming above ~150–250 °C helps; hot work at 900–1150 °C and avoid slow cooling through 550–400 °C to prevent 475 °C embrittlement.
What is the maximum service temperature of 446 Hot Rolled?
446 Hot Rolled 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.
Can FabDigit make parts in 446 Hot Rolled?
Yes — 446 Hot Rolled is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM International (2023)
- ASTM A176 — Stainless and Heat-Resisting Chromium Steel Plate, Sheet, and Strip — ASTM International (2022)
- ASTM A276 — Stainless Steel Bars and Shapes — ASTM International (2023)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- GB/T 1220 / GB/T 4237 (2Cr25N ) — SAC (2015)
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.