Steel H41-AQ (As-quenched)
Heat-treated state
AISI/SAE H41 · UNS T20841
Intermediate condition only — brittle with retained austenite; must be double or triple tempered before use.
Values for the AQ condition
Other H41 tempers and conditions
H41 is listed in 6 conditions; see the grade overview at H41.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard mill-supplied condition: bar and block are machined and rough-formed here before hardening. | 540 | 800 | 20 | 217 HB | 26 W/m·K |
Hot rolled | Rough mill stock with scale and variable hardness — anneal before machining. | 760 | 1,010 | 11 | 31 HRC | 2.7 % IACS |
Hardened and tempered | Choose when shock loading dominates — hot heading dies, hot punches and hammer-forging inserts prone to gross cracking. | 1,450 | 1,750 | 7 | 52 HRC | — |
AQThis page As-quenched | Intermediate condition only — brittle with retained austenite; must be double or triple tempered before use. | 1,650 | 1,900 | 1 | 65 HRC | 2.4 % IACS |
Hardened and tempered | Balanced hot hardness and toughness for hot forging dies, mandrels and hot-extrusion dummy blocks working near 550–600 °C. | 1,750 | 2,100 | 4 | 57 HRC | 25 W/m·K |
Hardened and tempered | Maximum wear resistance and hot hardness for hot-shear blades, punches and extrusion tooling with low impact loading. | 2,050 | 2,400 | 2 | 61 HRC | 24 W/m·K |
What is H41-AQ?
H41-AQ is H41 heat treated to AQ — intermediate condition only — brittle with retained austenite; must be double or triple tempered before use. H41-AQ has a yield strength of 1,650 MPa (239 ksi) and a tensile strength of 1,900 MPa (276 ksi) — stronger than 99% of steel grades. Elongation at break is 1% and the elastic modulus is 215 GPa (31.2 Msi). H41-AQ has a density of 7.88 g/cm³ (0.285 lb/in³), heavier than 93% of steel grades. It melts at 1,370°C (2,498 °F). ANN is the default condition FabDigit quotes; AQ is available on request or by drawing note.
Advantages
- High strength — 1,650 MPa (239 ksi), better than 99% of steel grades
Limitations
- Difficult to machine — 5/100, worse than 100% of steel grades
- Difficult to weld — 5/100, worse than 100% of steel grades
- Limited formability — 2/100, worse than 100% of steel grades
- Limited ductility — 1%, worse than 99% of steel grades
- Low electrical conductivity — 2.4 % IACS, worse than 97% of steel grades
H41-AQ properties
Typical room-temperature values for H41-AQ; 23 are specific to this condition. Other listed values are H41 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
H41-AQ has a density of 7.88 g/cm³ (0.285 lb/in³), heavier than 93% of steel grades. It melts at 1,370°C (2,498 °F).
Mechanical14
H41-AQ has a yield strength of 1,650 MPa (239 ksi) and a tensile strength of 1,900 MPa (276 ksi) — stronger than 99% of steel grades. Elongation at break is 1% and the elastic modulus is 215 GPa (31.2 Msi).
Thermal6
H41-AQ is rated for continuous service to 200°C (392 °F). It conducts heat at 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
H41-AQ conducts electricity at 2.4 % IACS, worse than 97% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (16/100), better than 79% of steel grades.
Sustainability4
Producing a kilogram of H41-AQ takes about 42 MJ of energy and emits 3.1 kg of CO₂ — more than 92% of steel grades. Typical recycled content is 45%.
Manufacturability7
H41-AQ's machinability is not recommended (5/100, worse than 100% of steel grades); weldability not recommended (5/100); formability not recommended (2/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with H41-AQ
Is H41 easy to machine?
Machine only in the annealed condition (≈45% of AISI 1212) with rigid setups, cobalt HSS or coated carbide, generous coolant; leave 0.3–0.6 mm grinding stock for post-hardening finishing.
Can H41 be welded?
Repair-weld only with matching Mo-hot-work filler at 400–480 °C preheat, low heat input, and immediate re-temper 15–25 °C below the last tempering temperature.
Can H41 be formed, bent or molded?
Forge 1065–1150 °C, stop above 900 °C, slow-cool in furnace or vermiculite, then fully anneal at 845–870 °C to below 235 HB; cold forming is impractical.
What surface finishes work on H41?
Vacuum or salt-bath hardening with careful decarburization control; nitriding, oxidation-treatment or PVD (TiAlN/CrN) coatings markedly extend die life, and all surfaces need oil or phosphate protection against rust.
H41 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 | 0.55 – 0.7 | 0.65 |
| Mn | 0.15 – 0.4 | 0.3 |
| Si | 0.2 – 0.5 | 0.35 |
| Cr | 3.5 – 4 | 3.75 |
| Moprincipal hot-hardness element | 8 – 9 | 8.5 |
| W | 1.25 – 1.75 | 1.5 |
| V | 1 – 1.3 | 1.15 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
H41-AQ — frequently asked
What is H41-AQ used for?
H41-AQ is typically used for hot forging dies, extrusion tooling, die-casting components and hot trim dies. In short: low heat-treat distortion; best machinability of the H-group; molybdenum substitute for tungsten grades.
What is the yield strength of H41-AQ?
H41-AQ has a typical yield strength of 1,650 MPa (239 ksi) and a tensile strength of 1,900 MPa (276 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is H41-AQ easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 100% of steel grades). Machine only in the annealed condition (≈45% of AISI 1212) with rigid setups, cobalt HSS or coated carbide, generous coolant; leave 0.3–0.6 mm grinding stock for post-hardening finishing.
Can H41-AQ be welded?
Not readily — weldability is rated not recommended (5/100). Repair-weld only with matching Mo-hot-work filler at 400–480 °C preheat, low heat input, and immediate re-temper 15–25 °C below the last tempering temperature.
What surface finishes work on H41-AQ?
Vacuum or salt-bath hardening with careful decarburization control; nitriding, oxidation-treatment or PVD (TiAlN/CrN) coatings markedly extend die life, and all surfaces need oil or phosphate protection against rust.
Can H41-AQ be formed, bent or molded?
Forge 1065–1150 °C, stop above 900 °C, slow-cool in furnace or vermiculite, then fully anneal at 845–870 °C to below 235 HB; cold forming is impractical.
What is the maximum service temperature of H41-AQ?
H41-AQ 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.
What is the difference between H41-ANN and H41-HT60?
ANN is the default condition — standard mill-supplied condition: bar and block are machined and rough-formed here before hardening. HT60: maximum wear resistance and hot hardness for hot-shear blades, punches and extrusion tooling with low impact loading. Yield strength is 540 MPa in ANN versus 2,050 MPa in HT60.
Sources
- ASTM A681 — Standard Specification for Tool Steels Alloy — ASTM International (2022)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- Tool Steels, 5th Edition (Roberts, Krauss, Kennedy) — ASM International (1998)
- UNS T20841 alloy record — SAE/ASTM Unified Numbering System (2017)
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.