Stainless Steel 440B · heat-treated state
Stainless Steel 440B Hardened & Tempered
Properties of the Hardened & Tempered condition, compared with the other 440B tempers.
The standard service condition for blades, valve seats and wear parts: maximum hardness, wear resistance and best corrosion resistance of the hardened states.
What is 440B Hardened & Tempered?
440B Hardened & Tempered is 440B heat treated to Hardened & Tempered — the standard service condition for blades, valve seats and wear parts: maximum hardness, wear resistance and best corrosion resistance of the hardened states. 440B Hardened & Tempered has a yield strength of 1,620 MPa (235 ksi) and a tensile strength of 1,860 MPa (270 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 3% and the elastic modulus is 200 GPa (29 Msi). 440B Hardened & Tempered has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 66% of stainless steel grades. It melts at 1,370°C (2,498 °F). Annealed is the default condition FabDigit quotes; Hardened & Tempered is available on request or by drawing note.
Advantages
- High strength — 1,620 MPa (235 ksi), better than 100% of stainless steel grades
- Polishes to a fine finish — 90/100, better than 100% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Conducts heat well — 24.2 W/m·K (14 BTU/hr·ft·°F), better than 84% of stainless steel grades
Limitations
- Limited ductility — 3%, worse than 100% of stainless steel grades
- Limited service temperature — 200°C (392 °F), worse than 100% of stainless steel grades
- Difficult to machine — 8/100, worse than 100% of stainless steel grades
- Difficult to weld — 10/100, worse than 100% of stainless steel grades
- Limited formability — 3/100, worse than 100% of stainless steel grades
440B Hardened & Tempered properties
Typical room-temperature values for 440B Hardened & Tempered — 19 properties are specific to this condition; the rest are grade-level values shared by every 440B temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
440B Hardened & Tempered has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 66% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical16
440B Hardened & Tempered has a yield strength of 1,620 MPa (235 ksi) and a tensile strength of 1,860 MPa (270 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 3% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
440B Hardened & Tempered is rated for continuous service to 200°C (392 °F). It conducts heat at 24.2 W/m·K (14 BTU/hr·ft·°F), better than 84% of stainless steel grades. Thermal expansion is 10.2 µm/m·K (5.67 µin/in·°F).
Electrical3
440B Hardened & Tempered conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 79% of stainless steel grades.
Sustainability4
Producing a kilogram of 440B Hardened & Tempered takes about 53 MJ of energy and emits 4.2 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 50%.
Manufacturability7
440B Hardened & Tempered's machinability is not recommended (8/100, worse than 100% of stainless steel grades); weldability not recommended (10/100); formability not recommended (3/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 440B tempers and conditions
440B is also supplied in 4 other conditions. The full side-by-side table is on the 440B overview.
- AnnealedDefaultStandard stock condition for bar, strip and blanks that will be machined and then hardened by the user.425 MPa yield · 220 HB
- Hardened + Cryo + Double TemperChoose for gauge-stable, maximum-hardness parts (bearing balls, precision cutlery) where retained austenite must be transformed.1,700 MPa yield · 58 HRC
- Hardened & TemperedThe standard service condition for blades, valve seats and wear parts: maximum hardness, wear resistance and best corrosion resistance of the hardened states.1,620 MPa yield · 56 HRC
- H&T 50-52 HRCSlightly tougher/lower-hardness option for shafts and highly stressed parts; corrosion resistance drops because of carbide precipitation, so avoid in wet chloride service.1,500 MPa yield · 51 HRC
- Annealed + Cold DrawnPick for close-tolerance bar, wire and shafting where slightly higher as-supplied strength and a better surface are needed before hardening.640 MPa yield · 26 HRC
Working with 440B Hardened & Tempered
Is 440B easy to machine?
Machine only in the annealed condition with rigid setups, sharp positive-rake carbide, low speed/heavy feed and flood coolant; hardened parts require grinding or EDM.
Can 440B be welded?
Poor weldability — preheat 200–300 °C, use matching or austenitic filler, and follow with a full anneal or hardening cycle to avoid HAZ cracking.
Can 440B be formed, bent or molded?
Only mild cold forming of annealed strip is practical; hot work at 1000–1150 °C with slow cooling and immediate anneal to prevent quench cracks.
What surface finishes work on 440B?
Harden, then grind and polish before final passivation; hardened surfaces take a mirror/edge finish, and hard chrome or nitriding is used only where extra wear life is needed.
440B 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 |
|---|---|---|
| Cdistinguishes 440B from 440A (0.60–0.75) and 440C (0.95–1.20) | 0.75 – 0.95 | 0.85 |
| Cr | 16 – 18 | 17 |
| Mn | ≤ 1 | 0.4 |
| Si | ≤ 1 | 0.4 |
| Momax; optional, aids hardenability | ≤ 0.75 | 0.4 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Fe | balance | — |
440B Hardened & Tempered — frequently asked
What is 440B Hardened & Tempered used for?
440B Hardened & Tempered is typically used for kitchen knife blades, pocket knife and folder blades, scissors and shear blades, valve seats and wear plates, bearing balls and races and surgical and dental instruments. In short: cutlery-grade hardenable stainless.
What is the yield strength of 440B Hardened & Tempered?
440B Hardened & Tempered has a typical yield strength of 1,620 MPa (235 ksi) and a tensile strength of 1,860 MPa (270 ksi) — stronger than 100% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 440B Hardened & Tempered easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 100% of stainless steel grades). Machine only in the annealed condition with rigid setups, sharp positive-rake carbide, low speed/heavy feed and flood coolant; hardened parts require grinding or EDM.
Can 440B Hardened & Tempered be welded?
Not readily — weldability is rated not recommended (10/100). Poor weldability — preheat 200–300 °C, use matching or austenitic filler, and follow with a full anneal or hardening cycle to avoid HAZ cracking.
What surface finishes work on 440B Hardened & Tempered?
Harden, then grind and polish before final passivation; hardened surfaces take a mirror/edge finish, and hard chrome or nitriding is used only where extra wear life is needed.
Can 440B Hardened & Tempered be formed, bent or molded?
Only mild cold forming of annealed strip is practical; hot work at 1000–1150 °C with slow cooling and immediate anneal to prevent quench cracks.
What is the maximum service temperature of 440B Hardened & Tempered?
440B Hardened & Tempered is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 440B Hardened & Tempered?
Yes — 440B Hardened & Tempered is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A276/A276M Stainless Steel Bars and Shapes — ASTM (2023)
- EN 10088-3 (X90CrMoV18, 1.4112) — CEN (2014)
- JIS G 4303 (SUS440B) — JSA (2021)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels — ASM International (1990)
- 440A/440B/440C Stainless Steel Product Data Sheet — AK Steel / Cleveland-Cliffs (2016)
- GB/T 1220 (9Cr18) — SAC (2007)
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.