Steel 1.2311 · heat-treated state
Steel 1.2311 Prehard
Properties of the Prehard condition, compared with the other 1.2311 tempers.
Standard stock condition: machine the finished mould directly, no further heat treatment or distortion risk.
What is 1.2311 Prehard?
1.2311 Prehard is 1.2311 heat treated to Prehard — standard stock condition: machine the finished mould directly, no further heat treatment or distortion risk. 1.2311 Prehard has a yield strength of 860 MPa (125 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 89% of steel grades. Elongation at break is 14% and the elastic modulus is 205 GPa (29.7 Msi). 1.2311 Prehard 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). Annealed is the default condition FabDigit quotes; Prehard is available on request or by drawing note.
Advantages
- High strength — 860 MPa (125 ksi), better than 89% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
1.2311 Prehard properties
Typical room-temperature values for 1.2311 Prehard — 12 properties are specific to this condition; the rest are grade-level values shared by every 1.2311 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
1.2311 Prehard 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).
Mechanical16
1.2311 Prehard has a yield strength of 860 MPa (125 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 89% of steel grades. Elongation at break is 14% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal5
1.2311 Prehard is rated for continuous service to 350°C (662 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades. Thermal expansion is 12.4 µm/m·K (6.89 µin/in·°F).
Electrical3
1.2311 Prehard conducts electricity at 7.8 % IACS, worse than 58% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 1.2311 Prehard takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
1.2311 Prehard's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (50/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 1.2311 tempers and conditions
1.2311 is also supplied in 3 other conditions. The full side-by-side table is on the 1.2311 overview.
- AnnealedDefaultPick for heavy machining, deep cavity sinking or when the part will be hardened and tempered after machining.500 MPa yield · 20 HRC
- Q&TChoose when higher wear resistance or higher core strength than pre-hard is needed in small/medium sections; accept distortion and re-machining.1,150 MPa yield · 41 HRC
- PrehardStandard stock condition: machine the finished mould directly, no further heat treatment or distortion risk.860 MPa yield · 31 HRC
- Prehard+NitridedUse for abrasive or glass-filled plastics: nitrided case raises surface wear and corrosion resistance while the pre-hard core keeps its toughness.860 MPa yield · 31 HRC
Working with 1.2311 Prehard
Is 1.2311 easy to machine?
Machines well at 28–34 HRC with coated carbide (roughing ~120–180 m/min, rigid setup); avoid dwelling and use positive rake to prevent work hardening; EDM and deep-hole drilling are routine for cooling channels.
Can 1.2311 be welded?
Repair-weldable with matched low-alloy or maraging filler: preheat 300–350 °C, weld hot, then stress relieve ~30 °C below the last tempering temperature to avoid HAZ cracking.
Can 1.2311 be formed, bent or molded?
Not a forming grade — supplied as pre-hardened plate/block and shaped only by machining; hot work above 900 °C and slow-cool if re-forging.
What surface finishes work on 1.2311?
Takes a good hand polish to ~Ra 0.05 µm (lower than ESR grades due to inclusions); commonly gas/plasma nitrided or hard-chrome / electroless-nickel plated for wear and corrosion protection, and must be oiled in storage.
1.2311 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 |
|---|---|---|
| C | 0.35 – 0.45 | 0.4 |
| Si | 0.2 – 0.4 | 0.3 |
| Mn | 1.3 – 1.6 | 1.45 |
| Cr | 1.8 – 2.1 | 1.95 |
| Mo | 0.15 – 0.25 | 0.2 |
| P | ≤ 0.03 | — |
| Smax; the S-bearing free-machining version is 1.2312 (0.05–0.10 S) | ≤ 0.03 | — |
| Fe | balance | — |
1.2311 Prehard — frequently asked
What is 1.2311 Prehard used for?
1.2311 Prehard is typically used for injection mould cavity and core plates, mould inserts, bolsters and mould frames, rubber moulding tools, die-casting auxiliary components and tooling and jig plates. In short: workhorse mold-cavity plate.
What is the yield strength of 1.2311 Prehard?
1.2311 Prehard has a typical yield strength of 860 MPa (125 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 89% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.2311 Prehard easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machines well at 28–34 HRC with coated carbide (roughing ~120–180 m/min, rigid setup); avoid dwelling and use positive rake to prevent work hardening; EDM and deep-hole drilling are routine for cooling channels.
Can 1.2311 Prehard be welded?
With care — weldability is rated fair (50/100). Repair-weldable with matched low-alloy or maraging filler: preheat 300–350 °C, weld hot, then stress relieve ~30 °C below the last tempering temperature to avoid HAZ cracking.
What surface finishes work on 1.2311 Prehard?
Takes a good hand polish to ~Ra 0.05 µm (lower than ESR grades due to inclusions); commonly gas/plasma nitrided or hard-chrome / electroless-nickel plated for wear and corrosion protection, and must be oiled in storage.
Can 1.2311 Prehard be formed, bent or molded?
Not a forming grade — supplied as pre-hardened plate/block and shaped only by machining; hot work above 900 °C and slow-cool if re-forging.
What is the maximum service temperature of 1.2311 Prehard?
1.2311 Prehard is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.2311 Annealed and 1.2311 Prehard?
Annealed is the default condition — pick for heavy machining, deep cavity sinking or when the part will be hardened and tempered after machining. Prehard: standard stock condition: machine the finished mould directly, no further heat treatment or distortion risk. Yield strength is 500 MPa in Annealed versus 860 MPa in Prehard.
Can FabDigit make parts in 1.2311 Prehard?
Yes — 1.2311 Prehard is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- EN ISO 4957 — Tool steels (40CrMnMo7, 1.2311) — ISO/CEN (2018)
- GB/T 1299 — (3Cr2MnMo / P20 equivalent) — SAC (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Specialty Handbook — Tool Materials — ASM International (1995)
- Böhler M201 / Uddeholm Impax-class pre-hardened mould steel data — voestalpine / Uddeholm (2022)
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.