Steel 3Cr2Mo Q&T 48-52 HRC
Hardness band
GB 3Cr2Mo · AISI/SAE P20
Q&T 48-52 HRC = quenched and low-tempered to 48–52 HRC
Maximum attainable hardness for small sections; toughness and machinability drop sharply, EDM/grinding only.
Values for the Q&T 48-52 HRC condition
Other 3Cr2Mo tempers and conditions
3Cr2Mo is listed in 8 conditions; see the grade overview at 3Cr2Mo.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
soft annealed for deep machining/EDM before hardening | Pick when the mould will be through-hardened after roughing, or for maximum machinability. | 450 | 700 | 22 | 210 HB | — |
air cooled from austenitizing, intermediate strength | Used for bar stock and for grain refinement before final quench and temper. | 570 | 860 | 18 | 24 HRC | 8 % IACS |
PH 28-32 HRCDefault Pre-hardened 28–32 HRC | Default stock condition: machine the cavity directly, no further heat treatment or distortion risk. | 830 | 1,000 | 15 | 30 HRC | — |
Pre-hardened then gas/plasma nitrided surface | Pick for abrasive glass-filled resins: hard nitrided case on a 30 HRC tough core, minimal distortion. | 830 | 1,000 | 13 | 30 HRC | 8 % IACS |
Electroslag-remelted, pre-hardened 28–32 HRC | Choose when optical or high-gloss polish and low inclusion content are required in large cavities. | 850 | 1,020 | 17 | 30 HRC | 8 % IACS |
Pre-hardened 33–38 HRC | Choose for higher wear resistance and better texture/polish on large moulds where machining power allows. | 1,000 | 1,180 | 13 | 36 HRC | — |
Quenched and tempered to 40–44 HRC | For inserts and small cores needing extra wear resistance; machine soft, then harden and finish-grind/EDM. | 1,150 | 1,350 | 11 | 42 HRC | — |
Q&T 48-52 HRCThis page Quenched and low-tempered to 48–52 HRC | Maximum attainable hardness for small sections; toughness and machinability drop sharply, EDM/grinding only. | 1,450 | 1,700 | 8 | 50 HRC | — |
What is 3Cr2Mo Q&T 48-52 HRC?
3Cr2Mo Q&T 48-52 HRC is 3Cr2Mo heat treated to Q&T 48-52 HRC — maximum attainable hardness for small sections; toughness and machinability drop sharply, EDM/grinding only. 3Cr2Mo Q&T 48-52 HRC has a yield strength of 1,450 MPa (210 ksi) and a tensile strength of 1,700 MPa (247 ksi) — stronger than 97% of steel grades. Elongation at break is 8% and the elastic modulus is 210 GPa (30.5 Msi). 3Cr2Mo Q&T 48-52 HRC 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). PH 28-32 HRC is the default condition FabDigit quotes; Q&T 48-52 HRC is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 82/100, better than 98% of steel grades
- High strength — 1,450 MPa (210 ksi), better than 97% of steel grades
Limitations
- Difficult to machine — 20/100, worse than 97% of steel grades
- Limited ductility — 8%, worse than 95% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 90% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
3Cr2Mo Q&T 48-52 HRC properties
Typical room-temperature values for 3Cr2Mo Q&T 48-52 HRC; 12 are specific to this condition. Other listed values are 3Cr2Mo reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
3Cr2Mo Q&T 48-52 HRC 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
3Cr2Mo Q&T 48-52 HRC has a yield strength of 1,450 MPa (210 ksi) and a tensile strength of 1,700 MPa (247 ksi) — stronger than 97% of steel grades. Elongation at break is 8% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
3Cr2Mo Q&T 48-52 HRC is rated for continuous service to 200°C (392 °F). It conducts heat at 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 82% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
3Cr2Mo Q&T 48-52 HRC conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of 3Cr2Mo Q&T 48-52 HRC takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 35%.
Manufacturability6
3Cr2Mo Q&T 48-52 HRC's machinability is poor (20/100, worse than 97% of steel grades); weldability fair (40/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 3Cr2Mo Q&T 48-52 HRC
Is 3Cr2Mo easy to machine?
Cuts well at 28–32 HRC with coated carbide (roughing ~120–180 m/min); use rigid setups and avoid dwell to prevent work-hardened glazing, EDM finishing is routine.
Can 3Cr2Mo be welded?
Weldable for mould repair with matching low-alloy or 420-type filler at 200–300 °C preheat plus post-weld temper 20–30 °C below the original tempering temperature.
Can 3Cr2Mo be formed, bent or molded?
Not a cold-forming steel; hot forge 1050–850 °C followed by slow cool and annealing, then quench from 850–880 °C in oil and temper 550–650 °C for the pre-hardened level.
What surface finishes work on 3Cr2Mo?
Takes a good but not mirror polish (ESR quality is better), responds well to photo-etch texturing, and is commonly hard-chrome or nickel plated for corrosive resins and gloss surfaces.
3Cr2Mo 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 | 0.28 – 0.4 | 0.35 |
| Si | 0.2 – 0.8 | 0.4 |
| Mn | 0.6 – 1 | 0.8 |
| Cr | 1.4 – 2 | 1.7 |
| Mo | 0.3 – 0.55 | 0.45 |
| P | ≤ 0.03 | — |
| Smax; free-machining variants (3Cr2MnNiMo/718S) add S ~0.05-0.10 | ≤ 0.03 | — |
| Fe | balance | — |
3Cr2Mo Q&T 48-52 HRC — frequently asked
What is 3Cr2Mo Q&T 48-52 HRC used for?
3Cr2Mo Q&T 48-52 HRC is typically used for injection mold cavities, mold bases and die-casting dies. In short: industry-standard mold block steel; pre-hardened, no heat treatment; cheaper than stainless mold steels.
What is the yield strength of 3Cr2Mo Q&T 48-52 HRC?
3Cr2Mo Q&T 48-52 HRC has a typical yield strength of 1,450 MPa (210 ksi) and a tensile strength of 1,700 MPa (247 ksi) — stronger than 97% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 3Cr2Mo Q&T 48-52 HRC easy to machine?
Not especially — machinability is rated poor (20/100, worse than 97% of steel grades). Cuts well at 28–32 HRC with coated carbide (roughing ~120–180 m/min); use rigid setups and avoid dwell to prevent work-hardened glazing, EDM finishing is routine.
Can 3Cr2Mo Q&T 48-52 HRC be welded?
With care — weldability is rated fair (40/100). Weldable for mould repair with matching low-alloy or 420-type filler at 200–300 °C preheat plus post-weld temper 20–30 °C below the original tempering temperature.
What surface finishes work on 3Cr2Mo Q&T 48-52 HRC?
Takes a good but not mirror polish (ESR quality is better), responds well to photo-etch texturing, and is commonly hard-chrome or nickel plated for corrosive resins and gloss surfaces.
Can 3Cr2Mo Q&T 48-52 HRC be formed, bent or molded?
Not a cold-forming steel; hot forge 1050–850 °C followed by slow cool and annealing, then quench from 850–880 °C in oil and temper 550–650 °C for the pre-hardened level.
What is the maximum service temperature of 3Cr2Mo Q&T 48-52 HRC?
3Cr2Mo Q&T 48-52 HRC is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM A681 Standard Specification for Tool Steels Alloy (P20) — ASTM (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Specialty Handbook — Tool Materials — ASM International (1995)
- Pre-hardened plastic mould steel (P20/718 class) datasheet — Uddeholm / ASSAB (2021)
- P20/3Cr2Mo — Mysteel / 1688 (2025)
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.