Steel P20+Ni
P20+Ni (DIN 1.2738 / 40CrMnNiMo8-6-4) is a prehardened plastic mould steel based on P20 with about 1 % nickel added to raise hardenability, giving uniform 28–34 HRC in sections over 400 mm.
Values for the Annealed condition
P20+Ni tempers and conditions
P20+Ni is supplied in 5 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault softened, ≤235 HB | Pick the softened ≤235 HB delivery state when you will quench and temper in house or must remove heavy stock by rough machining or cold piercing. | 430 | 700 | 20 | 210 HB | — |
Pre-hardened | Use the pre-hardened and tempered 28–34 HRC (285–330 HB) supply state to rough and finish-mill cavities straight into production, with no later heat treatment and no distortion risk. | 860 | 1,000 | 14 | 31 HRC | — |
pre-hardened core + gas/plasma nitrided case (600–700 HV surface) | Specify gas or plasma nitriding over the pre-hardened core for a 600–700 HV surface when molding glass- or mineral-filled plastics; cavity wear and scratch resistance rise, core toughness is kept. | 860 | 1,000 | 10 | 31 HRC | 7.2 % IACS |
pre-hardened high hardness, 36–40 HRC (340–380 HB) | Pick the high-hardness pre-hardened grade at 36–40 HRC (340–380 HB), offered as 1.2738HH/TS, for medium and large molds needing more wear resistance yet still no heat treatment. | 1,050 | 1,230 | 12 | 38 HRC | — |
Quenched and tempered | Choose oil or air quenching from 840–870 °C plus tempering to 40–50 HRC for small inserts and slides needing more than pre-hardened hardness; leave stock for quench distortion. | 1,250 | 1,450 | 10 | 45 HRC | — |
What is P20+Ni?
P20+Ni (DIN 1.2738 / 40CrMnNiMo8-6-4) is a prehardened plastic mould steel based on P20 with about 1 % nickel added to raise hardenability, giving uniform 28–34 HRC in sections over 400 mm. Supplied prehardened, it allows cavities to be machined directly with no further heat treatment, and it polishes and EDMs well, so it is used for large injection moulds, blow moulds and die-cast mould bases. Corrosion resistance is poor (use rust-preventive oil or chrome plating), hardness is limited to roughly 40 HRC, and wear resistance is insufficient for highly glass-filled resins unless the surface is nitrided or plated. P20+Ni has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). P20+Ni has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 51% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
What is P20+Ni used for?
- Large injection mould cavities and cores
- Mould inserts
- Mould plates and bolsters
- Blow mould bodies
- Die-cast machine mould frames
- Textured cosmetic mould surfaces
- Slides and heel blocks
Advantages
- Easy to machine — 62/100, better than 89% of steel grades
Limitations
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades
P20+Ni properties
Typical room-temperature values for P20+Ni-Annealed; bars are the position among steel grades.
Physical3
P20+Ni has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical17
P20+Ni has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 51% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P20+Ni is rated for continuous service to 400°C (752 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical2
P20+Ni has an electrical resistivity of 2.4×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of P20+Ni takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability6
P20+Ni's machinability is good (62/100, better than 89% of steel grades); weldability fair (50/100); 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 steel family
Yield strength against density for every steel grade FabDigit runs. P20+Ni is highlighted; hover a dot for its name, or open the interactive family chart.
Working with P20+Ni
Is P20+Ni easy to machine?
At the prehardened 30 HRC level it can be milled directly with coated carbide, positive-rake geometry and ample coolant; stress-relieve large blocks at about 550 °C before deep cavity cutting to limit distortion.
Can P20+Ni be welded?
Repair welding requires 300–350 °C preheat with interpass temperature held, matched P20/1.2738 filler, and stress-relief tempering at about 500–550 °C immediately after welding.
Can P20+Ni be formed, bent or molded?
Not a cold-forming material; hot work between 1050 and 850 °C, then slow cool and anneal. Finished geometry is produced by cutting and EDM.
Manufacturability
The process limits FabDigit applies to P20+Ni. Every P20+Ni part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better62 / 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 |
P20+Ni 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 |
|---|---|---|
| CDIN 40CrMnNiMo8-6-4 | 0.35 – 0.45 | 0.4 |
| Si | 0.2 – 0.4 | 0.3 |
| Mn | 1.3 – 1.6 | 1.45 |
| P | ≤ 0.03 | |
| Smax; mirror-finish grade requires ≤ 0.005 | ≤ 0.03 | |
| Cr | 1.8 – 2.1 | 1.95 |
| Mo | 0.15 – 0.25 | 0.2 |
| Niadded versus P20; increases hardenability | 0.9 – 1.2 | 1.05 |
| Fe | balance |
What surface finishes work on P20+Ni?
Polishes to A2/B1 mirror level, with ESR material giving the best results; nitriding, hard chrome or electroless nickel add wear and rust protection, and blasted or etched textures reproduce consistently.
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
How much does P20+Ni cost?
P20+Ni 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.
P20+Ni — frequently asked
What is P20+Ni used for?
P20+Ni is typically used for large injection mould cavities and cores, mould inserts, mould plates and bolsters, blow mould bodies, die-cast machine mould frames and textured cosmetic mould surfaces. In short: nickel-modified mold plate.
What is the yield strength of P20+Ni?
P20+Ni has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 51% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is P20+Ni easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). At the prehardened 30 HRC level it can be milled directly with coated carbide, positive-rake geometry and ample coolant; stress-relieve large blocks at about 550 °C before deep cavity cutting to limit distortion.
Can P20+Ni be welded?
With care — weldability is rated fair (50/100). Repair welding requires 300–350 °C preheat with interpass temperature held, matched P20/1.2738 filler, and stress-relief tempering at about 500–550 °C immediately after welding.
What surface finishes work on P20+Ni?
Polishes to A2/B1 mirror level, with ESR material giving the best results; nitriding, hard chrome or electroless nickel add wear and rust protection, and blasted or etched textures reproduce consistently.
Can P20+Ni be formed, bent or molded?
Not a cold-forming material; hot work between 1050 and 850 °C, then slow cool and anneal. Finished geometry is produced by cutting and EDM.
What is the maximum service temperature of P20+Ni?
P20+Ni 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 P20+Ni Annealed and P20+Ni Prehard?
Annealed is the default condition — pick the softened ≤235 HB delivery state when you will quench and temper in house or must remove heavy stock by rough machining or cold piercing. Prehard: use the pre-hardened and tempered 28–34 HRC (285–330 HB) supply state to rough and finish-mill cavities straight into production, with no later heat treatment and no distortion risk. Yield strength is 430 MPa in Annealed versus 860 MPa in Prehard.
How much does P20+Ni cost?
P20+Ni 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 P20+Ni?
Yes — P20+Ni 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
- DIN EN ISO 4957 Tool steels (40CrMnNiMo8-6-4 / 1.2738) — DIN/ISO (2018)
- GB/T 1299 3Cr2MnNiMo — SAC (2014)
- Prehardened plastic mould steel 1.2738 / 718 datasheet — Assab / voestalpine BÖHLER, Buderus Edelstahl (2022)
- ASM Handbook Vol.1 Properties and Selection: Irons, Steels — ASM International (1990)
- Tool Steels, 5th ed. — ASM International (1998)
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.