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Stainless Steel 440F · hardness band

Stainless Steel 440F Q&T 48-52 HRC

Properties of the Q&T 48-52 HRC condition, compared with the other 440F tempers.

Use when a little more toughness and dimensional stability is needed and peak hardness/corrosion resistance can be traded away.

CNC machiningStandard cost $$

What is 440F Q&T 48-52 HRC?

440F Q&T 48-52 HRC is 440F heat treated to Q&T 48-52 HRC — use when a little more toughness and dimensional stability is needed and peak hardness/corrosion resistance can be traded away. 440F Q&T 48-52 HRC has a yield strength of 1,480 MPa (215 ksi) and a tensile strength of 1,650 MPa (239 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 5% and the elastic modulus is 200 GPa (29 Msi). 440F Q&T 48-52 HRC has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,370°C (2,498 °F). Annealed is the default condition FabDigit quotes; Q&T 48-52 HRC is available on request or by drawing note.

Advantages

  • High strength — 1,480 MPa (215 ksi), better than 100% of stainless steel grades
  • Easy to machine — 55/100, better than 95% of stainless steel grades
  • Low embodied carbon — 3.4 kg CO₂/kg, better than 91% 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 — 5%, worse than 100% of stainless steel grades
  • Difficult to weld — 12/100, worse than 99% of stainless steel grades
  • Needs corrosion protection — 34/100, worse than 98% of stainless steel grades
  • Limited formability — 20/100, worse than 86% of stainless steel grades
  • Limited service temperature — 350°C (662 °F), worse than 84% of stainless steel grades

440F Q&T 48-52 HRC properties

Typical room-temperature values for 440F Q&T 48-52 HRC — 10 properties are specific to this condition; the rest are grade-level values shared by every 440F temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.

Physical3

440F Q&T 48-52 HRC has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,370°C (2,498 °F).

Density7.7 g/cm³0.28 lb/in³
Melting Point (Solidus)1,370°C2,498 °F
Liquidus Temperature1,425°C2,597 °F

Mechanical15

440F Q&T 48-52 HRC has a yield strength of 1,480 MPa (215 ksi) and a tensile strength of 1,650 MPa (239 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 5% and the elastic modulus is 200 GPa (29 Msi).

Elastic (Young's) Modulus200 GPa29 Msi
Shear Modulus77 GPa11.2 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.28
Tensile Strength (Ultimate)1,650 MPa239 ksi
Yield Strength (0.2% offset)1,480 MPa215 ksi
Elongation at Break5%
Reduction in Area25%
Compressive Strength430 MPa62.4 ksi
Shear Strength470 MPa68.2 ksi
Fatigue Strength (Endurance Limit)700 MPa102 ksi
Charpy V-Notch Impact (RT)9 J6.6 ft·lbf
Hardness, Brinell255 HB
Hardness, Rockwell B96 HRB
Hardness, Vickers520 HV

Thermal6

440F Q&T 48-52 HRC is rated for continuous service to 350°C (662 °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).

Thermal Conductivity24.2 W/m·K14 BTU/hr·ft·°F
Specific Heat Capacity460 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)10.2 µm/m·K5.7 µin/in·°F
Latent Heat of Fusion270 J/g116 BTU/lb
Max Service Temperature (continuous)350°C662 °F
Min Service Temperature-30°C-22 °F

Electrical3

440F Q&T 48-52 HRC conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.

Electrical Conductivity2.9 % IACS
Electrical Resistivity6×10⁻⁷ Ω·m23.6 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental3

Corrosion resistance is poor (34/100), worse than 98% of stainless steel grades.

Galvanic Potential (seawater, vs SCE)-0.25 V
Corrosion ResistancePoor34/100
Chemical Resistance SummaryAdequate in fresh water, mild atmospheres, petroleum products, alcohols and dilute organic acids when fully hardened and passivated; attacked by chlorides, seawater, acids and steam, and the MnS stringers act as pitting initiation sites, so it is clearly inferior to 440C and to austenitic 304/316.

Sustainability4

Producing a kilogram of 440F Q&T 48-52 HRC takes about 53 MJ of energy and emits 3.4 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 40%.

Embodied Energy (primary production)53 MJ/kg22,786 BTU/lb
Embodied Carbon (primary production)3.4 kg CO₂/kg
Embodied Water90 L/kg10.8 gal/lb
Typical Recycled Content40%

Manufacturability6

440F Q&T 48-52 HRC's machinability is good (55/100, better than 95% of stainless steel grades); weldability not recommended (12/100); formability poor (20/100).

MachinabilityGood55/100
Machinability Rating (AISI 1212 = 100 %)15%
WeldabilityNot recommended12/100
Formability (cold)Poor20/100
Brazeability / SolderabilityFair40/100
PolishabilityGood60/100

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Other 440F tempers and conditions

440F is also supplied in 3 other conditions. The full side-by-side table is on the 440F overview.

Working with 440F Q&T 48-52 HRC

Is 440F easy to machine?

Best machining of the 440 family — run annealed with rigid setups, positive-rake carbide, moderate speeds and heavy soluble-oil coolant; expect abrasive wear from Cr-carbides and grind after hardening.

Can 440F be welded?

Not recommended: high carbon plus high sulfur cause hot cracking and hard, brittle HAZ; if unavoidable, preheat 200–300 °C, use 309/310 filler and anneal immediately.

Can 440F be formed, bent or molded?

Cold forming is essentially limited to light straightening; hot work 1150→900 °C followed by slow cooling and a full anneal to avoid quench cracks.

What surface finishes work on 440F?

Harden, temper and passivate (nitric or citric) for usable corrosion resistance; hard chrome or electroless nickel is common for wear/corrosion duty, and sulfide stringers keep it from taking a true mirror polish.

440F 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.

ElementSpec limit (wt %)Nominal
Chigh carbon gives Cr-carbides for hardness/wear0.95 – 1.21.05
Cr16 – 1817
Mn≤ 1.250.8
Si≤ 10.5
Sfree-machining addition (MnS); Se-bearing 440F Se variant substitutes ≥0.15 % Se≥ 0.150.2
P≤ 0.060.03
Mooptional; may be added to aid machinability/hardenability≤ 0.60.4
Febalance

440F Q&T 48-52 HRC — frequently asked

What is 440F Q&T 48-52 HRC used for?

440F Q&T 48-52 HRC is typically used for cutlery, surgical instruments and knife blanks. In short: free-machining cutlery stainless.

What is the yield strength of 440F Q&T 48-52 HRC?

440F Q&T 48-52 HRC has a typical yield strength of 1,480 MPa (215 ksi) and a tensile strength of 1,650 MPa (239 ksi) — stronger than 100% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.

Is 440F Q&T 48-52 HRC easy to machine?

Reasonably — machinability is rated good (55/100, better than 95% of stainless steel grades). Best machining of the 440 family — run annealed with rigid setups, positive-rake carbide, moderate speeds and heavy soluble-oil coolant; expect abrasive wear from Cr-carbides and grind after hardening.

Can 440F Q&T 48-52 HRC be welded?

Not readily — weldability is rated not recommended (12/100). Not recommended: high carbon plus high sulfur cause hot cracking and hard, brittle HAZ; if unavoidable, preheat 200–300 °C, use 309/310 filler and anneal immediately.

What surface finishes work on 440F Q&T 48-52 HRC?

Harden, temper and passivate (nitric or citric) for usable corrosion resistance; hard chrome or electroless nickel is common for wear/corrosion duty, and sulfide stringers keep it from taking a true mirror polish.

Can 440F Q&T 48-52 HRC be formed, bent or molded?

Cold forming is essentially limited to light straightening; hot work 1150→900 °C followed by slow cooling and a full anneal to avoid quench cracks.

What is the maximum service temperature of 440F Q&T 48-52 HRC?

440F Q&T 48-52 HRC is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between 440F Annealed and 440F-ACD?

Annealed is the default condition — stock condition for high-volume screw-machine work; parts are machined soft then hardened and tempered. ACD: pick for close-tolerance, bright-finish bar feeding CNC lathes when a slightly higher as-machined strength is acceptable. Yield strength is 415 MPa in Annealed versus 620 MPa in ACD.

Can FabDigit make parts in 440F Q&T 48-52 HRC?

Yes — 440F Q&T 48-52 HRC is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.

Sources

  1. ASTM A582/A582M — Free-Machining Stainless Steel BarsASTM International (2021)
  2. EN 10088-3 (X70CrMo15 / 1.4109 related martensitic grades)CEN (2014)
  3. ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance AlloysASM International (1990)
  4. ASM Specialty Handbook — Stainless SteelsASM International (1994)
  5. Martensitic free-machining stainless bar datasheets (440C/440F class)Various bar producers (2023)

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.