Steel 420 Mod Mold
EN 1.2083, X42Cr13 · GB 3Cr13Mo · also Stavax ESR
420 Mod is a vacuum/ESR-refined, chromium-enriched martensitic stainless tool steel (1.2083, X42Cr13, S42000; also cross-referenced to SUS420J2, 3Cr13Mo and Stavax ESR) supplied annealed, prehardened, or hardened to 52–54 HRC.
Values for the Annealed condition
420 Mod Mold tempers and conditions
420 Mod Mold is supplied in 4 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft annealed, ≤235 HB | Standard stock condition for shops that will rough-machine and then harden the cavity themselves. | 470 | 760 | 19 | 220 HB | — |
Pre-hardened | Pick for cavity/core blocks machined to final shape with no further heat treatment and no distortion risk. | 860 | 1,030 | 13 | 31 HRC | — |
Quenched and tempered | Use for high-wear, high-gloss cavities and inserts running abrasive or glass-filled resins. | 1,450 | 1,750 | 7 | 50 HRC | — |
Q&T 52–54 HRC | Top-hardness option for small inserts, gate areas and wear-critical details where toughness is secondary. | 1,600 | 1,900 | 4 | 53 HRC | — |
What is 420 Mod Mold?
420 Mod is a vacuum/ESR-refined, chromium-enriched martensitic stainless tool steel (1.2083, X42Cr13, S42000; also cross-referenced to SUS420J2, 3Cr13Mo and Stavax ESR) supplied annealed, prehardened, or hardened to 52–54 HRC. Engineers specify it for plastic-mold cavities, inserts and precision tooling that must hold a mirror polish in humid or corrosive service, usually as plate and blocks. Annealed values are about 470 MPa yield, 760 MPa tensile, 19 % elongation and 220 HB, with service to roughly 400 °C and a corrosion-resistance score of 45, below austenitic stainless. Standard 420 costs less where ESR cleanliness and A1 polish are not required. 420 Mod Mold has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 93% of steel grades. It melts at 1,425°C (2,597 °F). 420 Mod Mold has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 57% of steel grades. Elongation at break is 19% and the elastic modulus is 200 GPa (29 Msi).
What is 420 Mod Mold used for?
- Plastic injection-mold cavities and cores
- Optical-part molds
- Mold inserts for PVC and other corrosive polymers
- Blow-mold cavities
- Extrusion dies for plastics
- Medical and packaging mold tooling
- Precision gauges and fixtures
Advantages
- Polishes to a fine finish — 90/100, better than 100% of steel grades
- Good corrosion resistance — 45/100, better than 98% of steel grades
Limitations
- High embodied carbon — 3.6 kg CO₂/kg, worse than 94% of steel grades
- Poor heat conductor — 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades
- Low electrical conductivity — 3.1 % IACS, worse than 89% of steel grades
- Difficult to weld — 25/100, worse than 77% of steel grades
420 Mod Mold properties
Typical room-temperature values for 420 Mod Mold-Annealed; bars are the position among steel grades.
Physical3
420 Mod Mold has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 93% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
420 Mod Mold has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 57% of steel grades. Elongation at break is 19% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
420 Mod Mold is rated for continuous service to 400°C (752 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
420 Mod Mold conducts electricity at 3.1 % IACS, worse than 89% of steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), better than 98% of steel grades.
Sustainability4
Producing a kilogram of 420 Mod Mold takes about 52 MJ of energy and emits 3.6 kg of CO₂ — more than 94% of steel grades. Typical recycled content is 60%.
Manufacturability7
420 Mod Mold's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (25/100); formability fair (35/100).
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 steel family
Yield strength against density for every steel grade FabDigit runs. 420 Mod Mold is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 420 Mod Mold
Is 420 Mod Mold easy to machine?
Machine in the annealed or prehard state with rigid setups, sharp coated carbide and generous coolant — the alloy work-hardens and gums at low speeds; hardened 50 HRC parts need CBN/hard-milling or EDM.
Can 420 Mod Mold be welded?
TIG repair only with matching 420-type or 410NiMo filler, preheat 250–325 °C, weld hot and temper immediately below the last tempering temperature to avoid cracking.
Can 420 Mod Mold be formed, bent or molded?
Not a cold-forming grade; hot work 1100→850 °C with slow cooling, then soft anneal at ~850 °C furnace-cooled before machining.
Manufacturability
The process limits FabDigit applies to 420 Mod Mold. Every 420 Mod Mold part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better45 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
420 Mod Mold 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 |
|---|---|---|
| Craised vs standard 420 for full hardening | 0.33 – 0.45 | 0.38 |
| Si | 0.2 – 1 | 0.4 |
| Mn | 0.3 – 1 | 0.5 |
| Cr | 12.5 – 14.5 | 13.5 |
| Momodification for hardenability/temper resistance | 0 – 0.6 | 0.3 |
| Vgrain refinement, wear resistance | 0 – 0.4 | 0.25 |
| Nioptional, toughness in heavy sections | 0 – 0.6 | 0.25 |
| P | ≤ 0.03 | |
| Skept very low (ESR) for polishability | ≤ 0.01 | 0 |
| Fe | balance |
What surface finishes work on 420 Mod Mold?
Excellent mirror (A1) polishability in the hardened ESR condition; stress-relieve before finish machining and consider nitriding, PVD CrN/TiN or hard chrome for extra wear resistance — no anodizing on steel.
Surface treatments FabDigit runs on 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
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 420 Mod Mold in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.2083X42Cr13
- GB (China)
- 3Cr13Mo
- Trade names
- Stavax ESR
- Similar grades
- 420 ModSUS420J2S42000
How much does 420 Mod Mold cost?
420 Mod Mold is a standard-cost steel ($$), cheaper than about 59% 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.
420 Mod Mold — frequently asked
What is 420 Mod Mold used for?
420 Mod Mold is typically used for plastic injection-mold cavities and cores, optical-part molds, mold inserts for PVC and other corrosive polymers, blow-mold cavities, extrusion dies for plastics and medical and packaging mold tooling. In short: modified mold-cavity plate.
What is the yield strength of 420 Mod Mold?
420 Mod Mold has a typical yield strength of 470 MPa (68.2 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 57% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is 420 Mod Mold easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed or prehard state with rigid setups, sharp coated carbide and generous coolant — the alloy work-hardens and gums at low speeds; hardened 50 HRC parts need CBN/hard-milling or EDM.
Can 420 Mod Mold be welded?
Not readily — weldability is rated poor (25/100). TIG repair only with matching 420-type or 410NiMo filler, preheat 250–325 °C, weld hot and temper immediately below the last tempering temperature to avoid cracking.
What surface finishes work on 420 Mod Mold?
Excellent mirror (A1) polishability in the hardened ESR condition; stress-relieve before finish machining and consider nitriding, PVD CrN/TiN or hard chrome for extra wear resistance — no anodizing on steel.
Can 420 Mod Mold be formed, bent or molded?
Not a cold-forming grade; hot work 1100→850 °C with slow cooling, then soft anneal at ~850 °C furnace-cooled before machining.
What is the maximum service temperature of 420 Mod Mold?
420 Mod Mold 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 420 Mod Mold Annealed and 420 Mod Mold Prehard?
Annealed is the default condition — standard stock condition for shops that will rough-machine and then harden the cavity themselves. Prehard: pick for cavity/core blocks machined to final shape with no further heat treatment and no distortion risk. Yield strength is 470 MPa in Annealed versus 860 MPa in Prehard.
How much does 420 Mod Mold cost?
420 Mod Mold is a standard-cost steel ($$), cheaper than about 59% 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 420 Mod Mold?
Yes — 420 Mod Mold 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
- ASTM A681 — Alloy Tool Steels — ASTM International (2015)
- GB/T 1299 / GB/T 1220 (4Cr13, 4Cr13 ) — SAC (2014)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Stainless plastic mould steel datasheets (13% Cr ESR mould grades) — Tool steel producers (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.