Steel H10-QT4448
Hardness band
AISI/SAE H10 · UNS T20810
QT4448 = q&T 44–48 HRC
The usual hardened working condition: best balance of hot strength, heat-checking resistance and toughness for Al die-casting dies.
Values for the QT4448 condition
Other H10 tempers and conditions
H10 is listed in 6 conditions; see the grade overview at H10.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard mill supply condition for bar, plate and forged blocks; machine the die cavity here, then harden. | 500 | 780 | 22 | 210 HB | 30 W/m·K |
ESR (electroslag remelted), annealed | Pick for large die-casting blocks needing isotropic toughness, low inclusion content and mirror polishability. | 500 | 780 | 24 | 14 HRC | 3.3 % IACS |
Q&T 40–44 HRC | Choose for large hot-forging dies and extrusion tooling where impact and gross cracking dominate over wear. | 1,150 | 1,350 | 12 | 42 HRC | 29 W/m·K |
QT4448This page Q&T 44–48 HRC | The usual hardened working condition: best balance of hot strength, heat-checking resistance and toughness for Al die-casting dies. | 1,350 | 1,570 | 10 | 46 HRC | 28 W/m·K |
Q&T 48–52 HRC | Use for hot punches, mandrels and shear blades where abrasion and hot compressive strength matter more than impact toughness. | 1,520 | 1,800 | 7 | 50 HRC | 27 W/m·K |
As-quenched | Transient condition only — must be tempered immediately; never used in service because of retained austenite and quench stresses. | 1,550 | 2,000 | 2 | 55 HRC | 3 % IACS |
What is H10-QT4448?
H10-QT4448 is H10 heat treated to QT4448 — the usual hardened working condition: best balance of hot strength, heat-checking resistance and toughness for Al die-casting dies. H10-QT4448 has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,570 MPa (228 ksi) — stronger than 95% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). H10-QT4448 has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,425°C (2,597 °F). ANN is the default condition FabDigit quotes; QT4448 is available on request or by drawing note.
Advantages
- High service temperature — 590°C (1,094 °F), better than 97% of steel grades
- High strength — 1,350 MPa (196 ksi), better than 95% of steel grades
- Polishes to a fine finish — 78/100, better than 95% of steel grades
- Good corrosion resistance — 25/100, better than 92% of steel grades
Limitations
- Limited formability — 3/100, worse than 99% of steel grades
- Difficult to machine — 22/100, worse than 95% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Low electrical conductivity — 3.3 % IACS, worse than 86% of steel grades
H10-QT4448 properties
Typical room-temperature values for H10-QT4448; 21 are specific to this condition. Other listed values are H10 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
H10-QT4448 has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical14
H10-QT4448 has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,570 MPa (228 ksi) — stronger than 95% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
H10-QT4448 is rated for continuous service to 590°C (1,094 °F). It conducts heat at 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 85% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
H10-QT4448 conducts electricity at 3.3 % IACS, worse than 86% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 92% of steel grades.
Sustainability4
Producing a kilogram of H10-QT4448 takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 45%.
Manufacturability7
H10-QT4448's machinability is poor (22/100, worse than 95% of steel grades); weldability poor (30/100); formability not recommended (3/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with H10-QT4448
Is H10 easy to machine?
Machine fully in the annealed condition with rigid setups and carbide tooling; after hardening above ~45 HRC use EDM, grinding or ceramic/CBN tools and stress-relieve after EDM.
Can H10 be welded?
Weldable for die repair with matched hot-work filler at 300–350 °C preheat, interpass held above preheat, slow cool and a temper 20–30 °C below the last tempering temperature.
Can H10 be formed, bent or molded?
Hot-work only: forge at 1050–1150 °C, stop above ~900 °C and slow-cool/anneal at 800–860 °C; cold forming is not practical.
What surface finishes work on H10?
Nitride, gas nitrocarburize or PVD-coat working faces for soldering and erosion resistance; polish/EDM-skin removal before nitriding; keep oiled since the steel is not stainless.
H10 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 |
|---|---|---|
| CASTM A681 H10; DIN 1.2365 is leaner at 0.28–0.35 C | 0.35 – 0.45 | 0.4 |
| Si1.2365 typically 0.10–0.40 Si | 0.8 – 1.2 | 1 |
| Mn | 0.25 – 0.7 | 0.4 |
| Cr | 3 – 3.75 | 3.3 |
| Mosecondary hardening / hot strength | 2 – 3 | 2.5 |
| Vgrain refinement, wear resistance | 0.25 – 0.75 | 0.45 |
| Niresidual max | ≤ 0.3 | — |
| Curesidual max | ≤ 0.25 | — |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
H10-QT4448 — frequently asked
What is H10-QT4448 used for?
H10-QT4448 is typically used for die-casting dies, hot forging dies, extrusion tooling and mandrels. In short: cr-Mo-V hot-work grade; good heat-check resistance; 500 °C service capability.
What is the yield strength of H10-QT4448?
H10-QT4448 has a typical yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,570 MPa (228 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is H10-QT4448 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of steel grades). Machine fully in the annealed condition with rigid setups and carbide tooling; after hardening above ~45 HRC use EDM, grinding or ceramic/CBN tools and stress-relieve after EDM.
Can H10-QT4448 be welded?
Not readily — weldability is rated poor (30/100). Weldable for die repair with matched hot-work filler at 300–350 °C preheat, interpass held above preheat, slow cool and a temper 20–30 °C below the last tempering temperature.
What surface finishes work on H10-QT4448?
Nitride, gas nitrocarburize or PVD-coat working faces for soldering and erosion resistance; polish/EDM-skin removal before nitriding; keep oiled since the steel is not stainless.
Can H10-QT4448 be formed, bent or molded?
Hot-work only: forge at 1050–1150 °C, stop above ~900 °C and slow-cool/anneal at 800–860 °C; cold forming is not practical.
What is the maximum service temperature of H10-QT4448?
H10-QT4448 is rated for continuous use to about 590°C (1,094 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between H10-ANN and H10-AQ?
ANN is the default condition — standard mill supply condition for bar, plate and forged blocks; machine the die cavity here, then harden. AQ: transient condition only — must be tempered immediately; never used in service because of retained austenite and quench stresses. Yield strength is 500 MPa in ANN versus 1,550 MPa in AQ.
Sources
- ASTM A681 Standard Specification for Tool Steels Alloy — ASTM International (2022)
- EN ISO 4957 Tool steels (X32CrMoV3-3 / 1.2365) — ISO/CEN (2018)
- GB/T 1299 (3Cr3Mo3W2V / 4Cr3Mo3SiV class) — SAC (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Hot-Work Tool Steels) — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating of Tool Steels — ASM International (1991)
- 1.2365 / H10 hot-work tool steel datasheet — Böhler / voestalpine (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.