Stainless Steel 420C
AISI/SAE 420C · UNS S42000 · EN 1.4034, X46Cr13 · GB 4Cr13
420C is a high-carbon 13% chromium martensitic stainless steel (EN 1.4034 / X46Cr13, AISI 420C, GB 4Cr13) that quench-and-tempers to 55–58 HRC for edge retention and wear resistance.
Values for the +A condition
420C tempers and conditions
420C is supplied in 7 conditions, soft to hard. +A is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ADefault Annealed | Stock condition for machining, blanking and subsequent hardening; lowest hardness and best machinability. | 460 | 760 | 17 | 20 HRC | — |
Quenched and tempered, 650–850 MPa class | High-temperature-tempered condition for shafts and structural parts needing ductility rather than wear resistance. | 500 | 750 | 14 | 21 HRC | 3.1 % IACS |
Cold drawn, annealed bar/wire | Choose for close-tolerance bright bar or wire that will be machined and then hardened. | 650 | 860 | 10 | 25 HRC | 3.1 % IACS |
Quenched and tempered, 800–1000 MPa class | Medium-strength Q&T condition where some impact toughness must be retained alongside higher strength. | 650 | 900 | 11 | 28 HRC | 3.1 % IACS |
hardened and tempered (moderate hardness) | Best hardness/toughness compromise for shear blades, valve components and moulds. | 1,300 | 1,550 | 6 | 48 HRC | — |
hardened and low-temperature tempered | Standard cutlery/surgical-blade condition: maximum wear resistance and edge retention with acceptable corrosion resistance. | 1,550 | 1,800 | 3 | 54 HRC | — |
Hardened | As-quenched martensite for maximum hardness; must normally be tempered/stress-relieved before service to avoid cracking. | 1,600 | 1,950 | 1 | 57 HRC | 2.5 % IACS |
Supply forms, finishes and certifications
Ways 420C is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CR+HT strip | Cold rolled hardened + tempered strip | Supply form |
What is 420C?
420C is a high-carbon 13% chromium martensitic stainless steel (EN 1.4034 / X46Cr13, AISI 420C, GB 4Cr13) that quench-and-tempers to 55–58 HRC for edge retention and wear resistance. It is supplied as bar, flat and cold-rolled strip; in the default annealed condition it gives 760 MPa tensile, 460 MPa yield, 17% elongation and about 220 HB (20 HRC). Corrosion resistance is moderate and depends on correct hardening, tempering and passivation, weldability is poor, and service is limited to about 400 °C. Choose 440C for higher hardness and wear life, or 410 where weldability matters more. 420C has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F). 420C has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 73% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 215 GPa (31.2 Msi).
What is 420C used for?
- Cutlery & blades
- Surgical instruments
- Bearings
Advantages
- Conducts heat well — 30 W/m·K (17.3 BTU/hr·ft·°F), better than 99% of stainless steel grades
- High electrical conductivity — 3.1 % IACS, better than 99% of stainless steel grades
- Low embodied carbon — 3.4 kg CO₂/kg, better than 91% of stainless steel grades
- Easy to machine — 45/100, better than 84% of stainless steel grades
Limitations
- Difficult to weld — 20/100, worse than 95% of stainless steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 91% of stainless steel grades
- Needs corrosion protection — 42/100, worse than 90% of stainless steel grades
- Limited ductility — 17%, worse than 86% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
420C properties
Typical room-temperature values for 420C-+A; bars are the position among stainless steel grades.
Physical3
420C has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical17
420C has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 73% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 215 GPa (31.2 Msi).
Thermal6
420C is rated for continuous service to 400°C (752 °F). It conducts heat at 30 W/m·K (17.3 BTU/hr·ft·°F), better than 99% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
420C conducts electricity at 3.1 % IACS, better than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (42/100), worse than 90% of stainless steel grades.
Sustainability4
Producing a kilogram of 420C takes about 50 MJ of energy and emits 3.4 kg of CO₂ — less than 80% of stainless steel grades. Typical recycled content is 45%.
Manufacturability8
420C's machinability is fair (45/100, better than 84% 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.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 420C is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 420C
Is 420C easy to machine?
Machine in the annealed condition with sharp, rigid carbide or HSS-Co tooling, moderate speed and heavy flood coolant; above ~45 HRC switch to CBN/ceramic turning or grinding/EDM.
Can 420C be welded?
Poor weldability — high carbon promotes hard, crack-prone martensite; if unavoidable, preheat 200–300 °C, use 410NiMo/309 filler, and temper immediately after welding.
Can 420C be formed, bent or molded?
Only light cold forming and blanking in the annealed state (generous bend radii, R ≥ 2t); hot work 1100–850 °C followed by slow cooling and full anneal to avoid quench cracks.
Manufacturability
The process limits FabDigit applies to 420C. Every 420C part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair45 / 100 |
|---|---|
| ISO material group | M.4 |
| Cutting speed (rough / finish) | 135 / 165 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1.5 mm |
| Drill depth limit | 4× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
420C 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 |
|---|---|---|
| CGB/T 1220 4Cr13 typically 0.36–0.45 %C | 0.43 – 0.5 | 0.46 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1 | 0.5 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 12.5 – 14.5 | 13.5 |
| Niresidual, not specified in all standards | ≤ 0.5 | 0.2 |
| Moresidual | ≤ 0.3 | |
| Fe | balance |
What surface finishes work on 420C?
Takes a mirror polish; harden, temper and then passivate (ASTM A967 nitric/citric) for best corrosion resistance — hard chrome, nitriding or PVD coatings are common for wear parts.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Organic Coating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 420C in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does 420C cost?
420C is a premium-cost stainless steel ($$$), cheaper than about 60% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
420C — frequently asked
What is 420C used for?
420C is typically used for cutlery & blades, surgical instruments and bearings. In short: high-carbon cutlery stainless.
What is the yield strength of 420C?
420C has a typical yield strength of 460 MPa (66.7 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 73% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 420C easy to machine?
Reasonably — machinability is rated fair (45/100, better than 84% of stainless steel grades). Machine in the annealed condition with sharp, rigid carbide or HSS-Co tooling, moderate speed and heavy flood coolant; above ~45 HRC switch to CBN/ceramic turning or grinding/EDM.
Can 420C be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — high carbon promotes hard, crack-prone martensite; if unavoidable, preheat 200–300 °C, use 410NiMo/309 filler, and temper immediately after welding.
What surface finishes work on 420C?
Takes a mirror polish; harden, temper and then passivate (ASTM A967 nitric/citric) for best corrosion resistance — hard chrome, nitriding or PVD coatings are common for wear parts.
Can 420C be formed, bent or molded?
Only light cold forming and blanking in the annealed state (generous bend radii, R ≥ 2t); hot work 1100–850 °C followed by slow cooling and full anneal to avoid quench cracks.
What is the maximum service temperature of 420C?
420C is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 420C +A and 420C-H?
+A is the default condition — stock condition for machining, blanking and subsequent hardening; lowest hardness and best machinability. H: as-quenched martensite for maximum hardness; must normally be tempered/stress-relieved before service to avoid cracking. Yield strength is 460 MPa in +A versus 1,600 MPa in H.
How much does 420C cost?
420C is a premium-cost stainless steel ($$$), cheaper than about 60% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in 420C?
Yes — 420C 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
- EN 10088-1/-2/-3 (X46Cr13, 1.4034) — CEN (2014)
- GB/T 1220 (4Cr13) — SAC (2007)
- ASTM A276/A582 (Type 420) — ASTM (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.13B / Vol.16 — Corrosion and Machining — ASM International (2005)
- Martensitic knife/blade strip datasheets (1.4034-class) — Alleima/Sandvik, Böhler (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.