Stainless Steel 420J2 Hardened & Tempered
Heat-treated state
EN 420J2 · UNS S42000 · JIS SUS420J2 · GB 3Cr13
Standard service condition for blades, instruments and valve parts — best balance of hardness, strength and corrosion resistance.
Values for the Hardened & Tempered condition
Other 420J2 tempers and conditions
420J2 is listed in 7 conditions; see the grade overview at 420J2.
- Annealed
- +QT800
- Cold Drawn
- Q&T 45-50 HRC
- Hardened & Tempered
- Hardened
- Q&T 50-55 HRC
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft annealed / subcritical annealed bar, plate and strip | Default stock condition for machining, blanking and forming before hardening. | 400 | 700 | 20 | 220 HB | — |
Hardened and tempered to Rm 800–950 MPa | European mechanical-property class for tempered bar/forgings where ductility and machinability matter more than hardness. | 650 | 880 | 12 | 27 HRC | — |
annealed then cold drawn/ground bar and wire | Pick for close-tolerance shafts and wire where extra strength and a bright surface are wanted without heat treatment. | 700 | 850 | 12 | 26 HRC | — |
Quenched and tempered ≈ 300–350 °C | Slightly softer, tougher condition for shafts, pump sleeves and mould inserts that see impact. | 1,300 | 1,550 | 8 | 47 HRC | — |
Hardened & TemperedThis page quench 1000–1050 °C, temper 200–300 °C (≈ 48–52 HRC) | Standard service condition for blades, instruments and valve parts — best balance of hardness, strength and corrosion resistance. | 1,450 | 1,720 | 6 | 50 HRC | 24 W/m·K |
stress-relieve only | Maximum hardness for wear-only parts; brittle and residual-stressed, so a low temper/stress relief is normally applied. | 1,550 | 1,900 | 2 | 55 HRC | — |
Quenched and tempered ≈ 150–200 °C | Choose for knife blades, scissors and wear surfaces where edge retention outranks toughness. | 1,550 | 1,850 | 4 | 53 HRC | — |
What is 420J2 Hardened & Tempered?
420J2 Hardened & Tempered is 420J2 heat treated to Hardened & Tempered — standard service condition for blades, instruments and valve parts — best balance of hardness, strength and corrosion resistance. 420J2 Hardened & Tempered has a yield strength of 1,450 MPa (210 ksi) and a tensile strength of 1,720 MPa (249 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 6% and the elastic modulus is 200 GPa (29 Msi). 420J2 Hardened & Tempered has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,450°C (2,642 °F). Annealed is the default condition FabDigit quotes; Hardened & Tempered is available on request or by drawing note.
Advantages
- High strength — 1,450 MPa (210 ksi), better than 99% of stainless steel grades
- High electrical conductivity — 3.1 % IACS, better than 99% of stainless steel grades
- Polishes to a fine finish — 85/100, better than 97% of stainless steel grades
- Low embodied carbon — 3.2 kg CO₂/kg, better than 95% of stainless steel grades
- Conducts heat well — 24.2 W/m·K (14 BTU/hr·ft·°F), better than 83% of stainless steel grades
Limitations
- Limited formability — 3/100, worse than 100% of stainless steel grades
- Limited ductility — 6%, worse than 99% of stainless steel grades
- Limited service temperature — 250°C (482 °F), worse than 99% of stainless steel grades
- Difficult to weld — 15/100, worse than 98% of stainless steel grades
- Difficult to machine — 22/100, worse than 95% of stainless steel grades
420J2 Hardened & Tempered properties
Typical room-temperature values for 420J2 Hardened & Tempered; 18 are specific to this condition. Other listed values are 420J2 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
420J2 Hardened & Tempered has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,450°C (2,642 °F).
Mechanical15
420J2 Hardened & Tempered has a yield strength of 1,450 MPa (210 ksi) and a tensile strength of 1,720 MPa (249 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 6% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
420J2 Hardened & Tempered is rated for continuous service to 250°C (482 °F). It conducts heat at 24.2 W/m·K (14 BTU/hr·ft·°F), better than 83% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
420J2 Hardened & Tempered conducts electricity at 3.1 % IACS, better than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (47/100), worse than 81% of stainless steel grades.
Sustainability4
Producing a kilogram of 420J2 Hardened & Tempered takes about 45 MJ of energy and emits 3.2 kg of CO₂ — less than 91% of stainless steel grades. Typical recycled content is 60%.
Manufacturability6
420J2 Hardened & Tempered's machinability is poor (22/100, worse than 95% of stainless steel grades); weldability poor (15/100); formability not recommended (3/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 420J2 Hardened & Tempered
Is 420J2 easy to machine?
Machine in the annealed condition with sharp, rigid tooling, moderate speed and generous coolant; hardened parts above ~45 HRC need carbide or CBN, or should be finished by grinding/EDM.
Can 420J2 be welded?
Poor weldability — preheat 200–300 °C, use matching or 309/310 filler, and temper immediately after welding to avoid cracking of the hard martensite.
Can 420J2 be formed, bent or molded?
Only light cold bending/blanking in the annealed state; harden at 1000–1050 °C, quench in oil or air, then temper at 150–350 °C (avoid 400–550 °C temper embrittlement).
What surface finishes work on 420J2?
Polishes to a mirror finish and is the standard choice for polished mould inserts; passivate or lightly oil after grinding, and consider hard chrome/PVD for extra corrosion or wear protection.
420J2 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 |
|---|---|---|
| CJIS SUS420J2 / GB 3Cr13; EN X30Cr13 is 0.26–0.35 | 0.26 – 0.4 | 0.32 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1 | 0.5 |
| P | ≤ 0.04 | 0.02 |
| SEN limit 0.015; free-machining variants up to 0.030 | ≤ 0.03 | 0.01 |
| Cr | 12 – 14 | 13 |
| Niresidual allowance (JIS/GB) | ≤ 0.6 | 0.3 |
| Fe | balance |
420J2 Hardened & Tempered — frequently asked
What is 420J2 Hardened & Tempered used for?
420J2 Hardened & Tempered is typically used for cutlery and kitchen knives, surgical scalpels and instruments, polished plastic mould inserts, scissors and shear blades, valve seats and needle valves and shafts and wear pins. In short: higher-carbon cutlery stainless.
What is the yield strength of 420J2 Hardened & Tempered?
420J2 Hardened & Tempered has a typical yield strength of 1,450 MPa (210 ksi) and a tensile strength of 1,720 MPa (249 ksi) — stronger than 99% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 420J2 Hardened & Tempered easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of stainless steel grades). Machine in the annealed condition with sharp, rigid tooling, moderate speed and generous coolant; hardened parts above ~45 HRC need carbide or CBN, or should be finished by grinding/EDM.
Can 420J2 Hardened & Tempered be welded?
Not readily — weldability is rated poor (15/100). Poor weldability — preheat 200–300 °C, use matching or 309/310 filler, and temper immediately after welding to avoid cracking of the hard martensite.
What surface finishes work on 420J2 Hardened & Tempered?
Polishes to a mirror finish and is the standard choice for polished mould inserts; passivate or lightly oil after grinding, and consider hard chrome/PVD for extra corrosion or wear protection.
Can 420J2 Hardened & Tempered be formed, bent or molded?
Only light cold bending/blanking in the annealed state; harden at 1000–1050 °C, quench in oil or air, then temper at 150–350 °C (avoid 400–550 °C temper embrittlement).
What is the maximum service temperature of 420J2 Hardened & Tempered?
420J2 Hardened & Tempered is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 420J2 Hardened & Tempered?
Yes — 420J2 Hardened & Tempered is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- JIS G 4303 — Stainless steel bars (SUS420J2) — JSA (2021)
- GB/T 1220 — Stainless steel bars (3Cr13/30Cr13) — SAC (2007)
- EN 10088-1 / 10088-3 — Stainless steels, X30Cr13 (1.4028) — CEN (2014)
- ASTM A276/A276M — Stainless steel bars and shapes (Type 420) — ASTM (2017)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Martensitic stainless 1.4028 / 420 bar and strip datasheets — Outokumpu / Sandvik (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.