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Stainless Steel 40Kh13-HR (Hot rolled)

Supply condition

EN 40Kh13 · AISI/SAE 420

Mill condition of hot bar and billet — hard and partly martensitic, normally annealed before machining.

Standard cost $$

Values for the HR condition

Other 40Kh13 tempers and conditions

40Kh13 is listed in 8 conditions; see the grade overview at 40Kh13.

Compare all 8 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
ADefault
Solution annealed
Standard stock condition for bar, strip and forging blanks — machine and form here, then harden.42070020200 HB—
HRThis page
Hot rolled
Mill condition of hot bar and billet — hard and partly martensitic, normally annealed before machining.6008801226 HRC—
Cold drawn
Choose for tight-tolerance ground/drawn bar and spring wire that will be hardened after machining.7209001027 HRC—
Q&T 600–680 °C
Structural condition for shafts, valve stems and fasteners where toughness and machinability matter more than hardness.7809801430 HRC—
Cold Rolled Hard strip
Precision strip supplied work-hardened for stamped blades and shims that are hardened after blanking.1,0501,250441 HRC2.8 % IACS
Q&T 400–500 °C
Spring, blade-back and valve-plate condition; accept the reduced impact toughness of the 475 °C embrittlement window.1,2501,500846 HRC—
Q&T 150–300 °C
The cutlery / surgical-instrument condition: maximum hardness, edge retention and corrosion resistance after polishing.1,4501,750551 HRC—
As-Quenched
Intermediate condition only — must be tempered or stress-relieved immediately to avoid quench cracking.1,5501,950255 HRC—

What is 40Kh13-HR?

40Kh13-HR is 40Kh13 supplied in the HR condition — mill condition of hot bar and billet — hard and partly martensitic, normally annealed before machining. 40Kh13-HR has a yield strength of 600 MPa (87 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 215 GPa (31.2 Msi). 40Kh13-HR has a density of 7.68 g/cm³ (0.277 lb/in³), lighter than 94% of stainless steel grades. It melts at 1,425°C (2,597 °F). A is the default condition FabDigit quotes; HR is available on request or by drawing note.

Advantages

  • Conducts heat well — 28.5 W/m·K (16.5 BTU/hr·ft·°F), better than 97% of stainless steel grades
  • High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
  • High strength — 600 MPa (87 ksi), better than 86% of stainless steel grades

Limitations

  • Needs corrosion protection — 35/100, worse than 97% of stainless steel grades
  • Limited ductility — 12%, worse than 95% of stainless steel grades
  • Difficult to weld — 25/100, worse than 92% of stainless steel grades
  • Limited formability — 15/100, worse than 91% of stainless steel grades
  • Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 88% of stainless steel grades

40Kh13-HR properties

Typical room-temperature values for 40Kh13-HR; 10 are specific to this condition. Other listed values are 40Kh13 reference data and may not represent this condition. Bars are the position among stainless steel grades.

Physical3

40Kh13-HR has a density of 7.68 g/cm³ (0.277 lb/in³), lighter than 94% of stainless steel grades. It melts at 1,425°C (2,597 °F).

Density7.68 g/cm³0.28 lb/in³
Melting Point (Solidus)1,425°C2,597 °F
Liquidus Temperature1,500°C2,732 °F

Mechanical16

40Kh13-HR has a yield strength of 600 MPa (87 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 215 GPa (31.2 Msi).

Elastic (Young's) Modulus215 GPa31.2 Msi
Shear Modulus83 GPa12 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.28
Tensile Strength (Ultimate)880 MPa128 ksi
Yield Strength (0.2% offset)600 MPa87 ksi
Elongation at Break12%
Reduction in Area45%
Compressive Strength720 MPa104 ksi
Shear Strength430 MPa62.4 ksi
Fatigue Strength (Endurance Limit)330 MPa47.9 ksi
Fracture Toughness (K_IC)60 MPa·√m54.6 ksi·√in
Charpy V-Notch Impact (RT)18 J13.3 ft·lbf
Hardness, Brinell265 HB
Hardness, Rockwell B94 HRB
Hardness, Vickers210 HV

Thermal6

40Kh13-HR is rated for continuous service to 550°C (1,022 °F). It conducts heat at 28.5 W/m·K (16.5 BTU/hr·ft·°F), better than 97% of stainless steel grades. Thermal expansion is 10.4 µm/m·K (5.78 µin/in·°F).

Thermal Conductivity28.5 W/m·K16.5 BTU/hr·ft·°F
Specific Heat Capacity460 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)10.4 µm/m·K5.8 µin/in·°F
Latent Heat of Fusion270 J/g116 BTU/lb
Max Service Temperature (continuous)550°C1,022 °F
Min Service Temperature-40°C-40 °F

Electrical3

40Kh13-HR 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 fair (35/100), worse than 97% of stainless steel grades.

Galvanic Potential (seawater, vs SCE)-0.3 V
Corrosion ResistanceFair35/100
Chemical Resistance SummaryResists fresh water, steam, atmosphere, alcohols, mild organic acids, blood and sterilisation media when hardened and well polished; attacked by chlorides, seawater, hydrochloric/sulphuric acids, and pits badly in the annealed or as-ground surface state.

Sustainability4

Producing a kilogram of 40Kh13-HR takes about 53 MJ of energy and emits 4.5 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 55%.

Embodied Energy (primary production)53 MJ/kg22,786 BTU/lb
Embodied Carbon (primary production)4.5 kg CO₂/kg
Embodied Water130 L/kg15.6 gal/lb
Typical Recycled Content55%

Manufacturability7

40Kh13-HR's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability poor (25/100); formability poor (15/100).

MachinabilityPoor30/100
Machinability Rating (AISI 1212 = 100 %)30%
WeldabilityPoor25/100
Formability (cold)Poor15/100
CastabilityFair40/100
Brazeability / SolderabilityFair45/100
PolishabilityVery good70/100

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with 40Kh13-HR

Is 40Kh13 easy to machine?

Machine in the annealed state with sharp, positive-rake carbide, rigid setups and generous coolant; above ~40 HRC switch to grinding, CBN or EDM.

Can 40Kh13 be welded?

Poor weldability — preheat 200–300 °C, use 410NiMo or austenitic filler, and temper/anneal immediately after welding to avoid cracks in the hard HAZ.

Can 40Kh13 be formed, bent or molded?

Cold form only in the annealed condition with generous bend radii (≥2t); hot work at 1100–850 °C followed by slow cooling and full anneal.

What surface finishes work on 40Kh13?

Harden and temper before final polishing, then passivate in nitric or citric acid; hard chrome, PVD or black oxide are common on cutlery and instruments.

40Kh13 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
C0.36 – 0.450.4
Si≤ 0.80.4
Mn≤ 0.80.4
Cr12 – 1413
Niresidual≤ 0.6—
Tiresidual≤ 0.2—
Curesidual≤ 0.3—
S≤ 0.03—
P≤ 0.03—
Febalance—

40Kh13-HR — frequently asked

What is 40Kh13-HR used for?

40Kh13-HR is typically used for surgical instruments, cutlery, springs and measuring tools. In short: hardenable 420-type stainless; edge-holding instrument grade; poor weldability.

What is the yield strength of 40Kh13-HR?

40Kh13-HR has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 86% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.

Is 40Kh13-HR easy to machine?

Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Machine in the annealed state with sharp, positive-rake carbide, rigid setups and generous coolant; above ~40 HRC switch to grinding, CBN or EDM.

Can 40Kh13-HR be welded?

Not readily — weldability is rated poor (25/100). Poor weldability — preheat 200–300 °C, use 410NiMo or austenitic filler, and temper/anneal immediately after welding to avoid cracks in the hard HAZ.

What surface finishes work on 40Kh13-HR?

Harden and temper before final polishing, then passivate in nitric or citric acid; hard chrome, PVD or black oxide are common on cutlery and instruments.

Can 40Kh13-HR be formed, bent or molded?

Cold form only in the annealed condition with generous bend radii (≥2t); hot work at 1100–850 °C followed by slow cooling and full anneal.

What is the maximum service temperature of 40Kh13-HR?

40Kh13-HR is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between 40Kh13-A and 40Kh13-Q?

A is the default condition — standard stock condition for bar, strip and forging blanks — machine and form here, then harden. Q: intermediate condition only — must be tempered or stress-relieved immediately to avoid quench cracking. Yield strength is 420 MPa in A versus 1,550 MPa in Q.

Sources

  1. GOST 5632-2014 Stainless steels and corrosion-resistant alloys — grades — Rosstandart (2014)
  2. GOST 5949-2018 Corrosion-resistant, heat-resistant steel bars and sections — Rosstandart (2018)
  3. GB/T 1220 (40Cr13) — SAC (2007)
  4. ASTM A276/A276M Stainless Steel Bars and Shapes (UNS S42000) — ASTM (2017)
  5. ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
  6. Marochnik stali i splavov — 40Х13 physical and mechanical data — Marochnik (2020)
  7. 1.4034 / X46Cr13 martensitic stainless datasheet — Böhler / Outokumpu (2021)

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.