Steel 4Cr5MoSiV QT 52-55 HRC
Hardness band
GB 4Cr5MoSiV · AISI/SAE H11
Only for small, well-supported wear parts; toughness is low and cracking risk in service is high.
Values for the QT 52-55 HRC condition
Other 4Cr5MoSiV tempers and conditions
4Cr5MoSiV is listed in 8 conditions; see the grade overview at 4Cr5MoSiV.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Electroslag remelted, annealed | Pick for large die-casting blocks, mirror-polished cavities and where NADCA-type cleanliness/isotropy is specified. | 490 | 760 | 24 | 14 HRC | 3.3 % IACS |
AnnealedDefault spheroidize annealed bar/plate (≤229 HB) | Standard as-supplied condition for machining before hardening; virtually all mill stock ships this way. | 500 | 780 | 22 | 210 HB | — |
Hot rolled | Cheapest mill form for large blocks that will be annealed and machined by the tool shop. | 700 | 1,000 | 14 | 31 HRC | 3.3 % IACS |
hardened and high-temper (max toughness) | Choose for large forging dies, die-casting holder blocks and shock-loaded tooling where cracking risk dominates over wear. | 1,150 | 1,350 | 13 | 42 HRC | — |
standard die-casting / extrusion die hardness | The default working hardness for aluminium die-casting dies and hot extrusion tooling — best balance of heat-check resistance and strength. | 1,300 | 1,550 | 11 | 46 HRC | — |
Nitrided surface (core Q&T 44–48 HRC) | Gas/plasma nitrided at 480–530 °C for extrusion dies and cores needing a wear- and soldering-resistant skin. | 1,350 | 1,550 | 8 | 46 HRC | 3.3 % IACS |
hardened and low-temper (max wear resistance) | For punches, shear blades, mandrels and small inserts where wear and compressive strength matter more than impact toughness. | 1,520 | 1,800 | 9 | 50 HRC | — |
QT 52-55 HRCThis page maximum attainable working hardness | Only for small, well-supported wear parts; toughness is low and cracking risk in service is high. | 1,650 | 1,950 | 7 | 54 HRC | — |
What is 4Cr5MoSiV QT 52-55 HRC?
4Cr5MoSiV QT 52-55 HRC is 4Cr5MoSiV heat treated to QT 52-55 HRC — only for small, well-supported wear parts; toughness is low and cracking risk in service is high. 4Cr5MoSiV QT 52-55 HRC has a yield strength of 1,650 MPa (239 ksi) and a tensile strength of 1,950 MPa (283 ksi) — stronger than 99% of steel grades. Elongation at break is 7% and the elastic modulus is 210 GPa (30.5 Msi). 4Cr5MoSiV QT 52-55 HRC has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F). Annealed is the default condition FabDigit quotes; QT 52-55 HRC is available on request or by drawing note.
Advantages
- High strength — 1,650 MPa (239 ksi), better than 99% of steel grades
- Polishes to a fine finish — 78/100, better than 95% of steel grades
- High service temperature — 480°C (896 °F), better than 88% of steel grades
Limitations
- Difficult to machine — 10/100, worse than 99% of steel grades
- Limited ductility — 7%, worse than 96% of steel grades
- Poor heat conductor — 24.5 W/m·K (14.2 BTU/hr·ft·°F), worse than 89% of steel grades
- Low electrical conductivity — 3.3 % IACS, worse than 86% of steel grades
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
4Cr5MoSiV QT 52-55 HRC properties
Typical room-temperature values for 4Cr5MoSiV QT 52-55 HRC; 11 are specific to this condition. Other listed values are 4Cr5MoSiV reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4Cr5MoSiV QT 52-55 HRC has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
4Cr5MoSiV QT 52-55 HRC has a yield strength of 1,650 MPa (239 ksi) and a tensile strength of 1,950 MPa (283 ksi) — stronger than 99% of steel grades. Elongation at break is 7% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
4Cr5MoSiV QT 52-55 HRC is rated for continuous service to 480°C (896 °F). It conducts heat at 24.5 W/m·K (14.2 BTU/hr·ft·°F), worse than 89% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
4Cr5MoSiV QT 52-55 HRC conducts electricity at 3.3 % IACS, worse than 86% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of 4Cr5MoSiV QT 52-55 HRC takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 45%.
Manufacturability8
4Cr5MoSiV QT 52-55 HRC's machinability is not recommended (10/100, worse than 99% of steel grades); weldability fair (35/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4Cr5MoSiV QT 52-55 HRC
Is 4Cr5MoSiV easy to machine?
Machine in the annealed condition (≤229 HB) with rigid setups and coated carbide; above 45 HRC switch to hard milling/EDM plus a stress-relief temper before final heat treatment.
Can 4Cr5MoSiV be welded?
Weldable for repair only with matching H11/H13 filler: preheat and hold at 300–400 °C, weld continuously, slow cool, then temper 20–30 °C below the last tempering temperature.
Can 4Cr5MoSiV be formed, bent or molded?
Hot work at 1050–1120 °C finishing above 900 °C with slow furnace cooling; cold forming is not practical — austenitize 1000–1030 °C, air/vacuum quench, and double or triple temper at 540–620 °C.
What surface finishes work on 4Cr5MoSiV?
Takes a high polish (best with ESR stock); protect service surfaces by nitriding, oxidation/blackening or PVD CrN/AlTiN — no anodizing, and hard chrome may spall under thermal cycling.
4Cr5MoSiV 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 | 0.33 – 0.43 | 0.38 |
| Si | 0.8 – 1.2 | 1 |
| Mn | 0.2 – 0.5 | 0.35 |
| Cr | 4.75 – 5.5 | 5.1 |
| Mo | 1.1 – 1.6 | 1.35 |
| V | 0.3 – 0.6 | 0.45 |
| P | ≤ 0.03 | — |
| Smax; premium/ESR often ≤0.005 | ≤ 0.03 | — |
| Niresidual, max | ≤ 0.3 | — |
| Curesidual, max | ≤ 0.25 | — |
| Fe | balance | — |
4Cr5MoSiV QT 52-55 HRC — frequently asked
What is 4Cr5MoSiV QT 52-55 HRC used for?
4Cr5MoSiV QT 52-55 HRC is typically used for die-casting dies, forging dies and hot shear blades. In short: tougher than H13; lower-carbon hot-work grade; polishes well in ESR quality.
What is the yield strength of 4Cr5MoSiV QT 52-55 HRC?
4Cr5MoSiV QT 52-55 HRC has a typical yield strength of 1,650 MPa (239 ksi) and a tensile strength of 1,950 MPa (283 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 4Cr5MoSiV QT 52-55 HRC easy to machine?
Not especially — machinability is rated not recommended (10/100, worse than 99% of steel grades). Machine in the annealed condition (≤229 HB) with rigid setups and coated carbide; above 45 HRC switch to hard milling/EDM plus a stress-relief temper before final heat treatment.
Can 4Cr5MoSiV QT 52-55 HRC be welded?
With care — weldability is rated fair (35/100). Weldable for repair only with matching H11/H13 filler: preheat and hold at 300–400 °C, weld continuously, slow cool, then temper 20–30 °C below the last tempering temperature.
What surface finishes work on 4Cr5MoSiV QT 52-55 HRC?
Takes a high polish (best with ESR stock); protect service surfaces by nitriding, oxidation/blackening or PVD CrN/AlTiN — no anodizing, and hard chrome may spall under thermal cycling.
Can 4Cr5MoSiV QT 52-55 HRC be formed, bent or molded?
Hot work at 1050–1120 °C finishing above 900 °C with slow furnace cooling; cold forming is not practical — austenitize 1000–1030 °C, air/vacuum quench, and double or triple temper at 540–620 °C.
What is the maximum service temperature of 4Cr5MoSiV QT 52-55 HRC?
4Cr5MoSiV QT 52-55 HRC is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4Cr5MoSiV Annealed and 4Cr5MoSiV-HR?
Annealed is the default condition — standard as-supplied condition for machining before hardening; virtually all mill stock ships this way. HR: cheapest mill form for large blocks that will be annealed and machined by the tool shop. Yield strength is 500 MPa in Annealed versus 700 MPa in HR.
Sources
- GB/T 1299 (4Cr5MoSiV) — SAC / (2014)
- ASTM A681 Standard Specification for Tool Steels Alloy (H11) — ASTM International (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Hot-Work Tool Steels) — ASM International (1990)
- Hot work tool steel W300 / H11 datasheet — voestalpine Böhler Edelstahl (2022)
- H11 / 1.2343 hot work die steel technical data — Daido Steel / (2021)
- H11/4Cr5MoSiV — Mysteel / 1688 (2026)
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.