Stainless Steel 440A · temper · default condition
Stainless Steel 440A Annealed
Properties of the Annealed condition, compared with the other 440A tempers.
Stock condition for machining, blanking and grinding before hardening.
What is 440A Annealed?
440A Annealed is 440A in the Annealed temper — stock condition for machining, blanking and grinding before hardening. 440A Annealed has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 725 MPa (105 ksi) — stronger than 62% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi). 440A Annealed has a density of 7.68 g/cm³ (0.277 lb/in³), lighter than 94% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Advantages
- 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
- Difficult to weld — 20/100, worse than 96% of stainless steel grades
- Needs corrosion protection — 48/100, worse than 81% of stainless steel grades
- Limited ductility — 20%, worse than 79% of stainless steel grades
- High embodied carbon — 5.5 kg CO₂/kg, worse than 77% of stainless steel grades
440A Annealed properties
Typical room-temperature values for 440A Annealed — 15 properties are specific to this condition; the rest are grade-level values shared by every 440A temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
440A Annealed has a density of 7.68 g/cm³ (0.277 lb/in³), lighter than 94% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical14
440A Annealed has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 725 MPa (105 ksi) — stronger than 62% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
440A Annealed is rated for continuous service to 760°C (1,400 °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
440A Annealed conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), worse than 81% of stainless steel grades.
Sustainability4
Producing a kilogram of 440A Annealed takes about 55 MJ of energy and emits 5.5 kg of CO₂ — less than 51% of stainless steel grades. Typical recycled content is 45%.
Manufacturability7
440A Annealed's machinability is fair (40/100, better than 73% of stainless steel grades); weldability poor (20/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 440A tempers and conditions
440A is also supplied in 6 other conditions. The full side-by-side table is on the 440A overview.
- AnnealedDefaultStock condition for machining, blanking and grinding before hardening.415 MPa yield · 195 HB
- H&T 150CMaximum hardness and edge retention with best corrosion resistance; lowest toughness.1,720 MPa yield · 56 HRC
- Hardened & TemperedGeneral service condition for blades, valve parts and wear components.1,650 MPa yield · 51 HRC
- H&T 315CStandard published H&T condition — balanced hardness, strength and toughness.1,650 MPa yield · 51 HRC
- H&T 600CUse only when higher toughness or elevated-temperature stability is needed; corrosion resistance drops.1,080 MPa yield · 40 HRC
- Cold DrawnPick for close-tolerance bright bar going straight to screw-machine work.620 MPa yield · 250 HB
Working with 440A Annealed
Is 440A easy to machine?
Machine only in the annealed condition with sharp, rigid, positive-rake carbide tooling and heavy coolant; hardened parts require grinding or EDM.
Can 440A be welded?
Poor weldability — preheat 200–315 °C, use matching or austenitic filler, and temper/anneal immediately after welding to avoid cracking.
Can 440A be formed, bent or molded?
Limited cold forming in the annealed state (simple bends with generous radii); hot work 1050–1150 °C and cool slowly to prevent cracking.
What surface finishes work on 440A?
Passivate (citric or nitric per ASTM A967) after hardening for full corrosion resistance; takes a fine mirror polish, and hard chrome or black oxide are common wear/cosmetic options.
440A 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 martensite + Cr carbides | 0.6 – 0.75 | 0.68 |
| Cr | 16 – 18 | 17 |
| Mn | ≤ 1 | 0.4 |
| Si | ≤ 1 | 0.4 |
| Mooptional | ≤ 0.75 | 0.3 |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
440A Annealed — frequently asked
What is 440A Annealed used for?
440A Annealed is typically used for diving and utility knife blades, cutlery blades, shear and slitting blades, valve components and seats, bearing races and surgical and medical instruments. In short: tough cutting stainless.
What is the yield strength of 440A Annealed?
440A Annealed has a typical yield strength of 415 MPa (60.2 ksi) and a tensile strength of 725 MPa (105 ksi) — stronger than 62% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 440A Annealed easy to machine?
Not especially — machinability is rated fair (40/100, better than 73% of stainless steel grades). Machine only in the annealed condition with sharp, rigid, positive-rake carbide tooling and heavy coolant; hardened parts require grinding or EDM.
Can 440A Annealed be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — preheat 200–315 °C, use matching or austenitic filler, and temper/anneal immediately after welding to avoid cracking.
What surface finishes work on 440A Annealed?
Passivate (citric or nitric per ASTM A967) after hardening for full corrosion resistance; takes a fine mirror polish, and hard chrome or black oxide are common wear/cosmetic options.
Can 440A Annealed be formed, bent or molded?
Limited cold forming in the annealed state (simple bends with generous radii); hot work 1050–1150 °C and cool slowly to prevent cracking.
What is the maximum service temperature of 440A Annealed?
440A Annealed is rated for continuous use to about 760°C (1,400 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 440A Annealed?
Yes — 440A Annealed 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 International (2023)
- JIS G 4303 — Stainless Steel Bars (SUS440A) — JSA (2021)
- EN 10088-3 (X70CrMo15, 1.4109) — CEN (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — 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.