Steel H11
AISI/SAE H11 · UNS T20811 · ASTM A681 · EN 1.2343 · GB 4Cr5MoSiV1, 4Cr5MoSiV
Vacuum-melted, vanadium-modified 5%Cr hot-work tool steel used in aerospace for high-strength structural forgings such as landing gear and rocket motor components, valued for hardenability and toughness at ~1900MPa.
Values for the Annealed condition
H11 tempers and conditions
H11 is supplied in 6 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault spheroidize annealed, soft supply condition | Standard mill-supply state for bar/plate that will be machined then hardened by the toolmaker. | 510 | 800 | 20 | 200 HB | — |
600–650 °C after rough machining | Intermediate step for large dies to minimise distortion before hardening; mechanical level stays near annealed. | 530 | 820 | 18 | 16 HRC | 3.3 % IACS |
Quenched and tempered | Standard working hardness for die-casting and extrusion dies where thermal-fatigue resistance and toughness matter most. | 1,300 | 1,550 | 12 | 46 HRC | — |
Q&T core plus gas/plasma nitrided case | Pick for die-casting cores and extrusion dies needing soldering/wear resistance; 0.1–0.3 mm case on a 44–48 HRC core. | 1,300 | 1,550 | 8 | 46 HRC | 3.3 % IACS |
Hot isostatic pressed | Use for AM or PM tooling where residual porosity must be closed; gives near-wrought toughness and isotropic properties. | 1,400 | 1,650 | 9 | 48 HRC | — |
laser powder bed fusion, as-built (self-quenched martensite) | AM 1.2343 straight off the machine: already hard and strong but low ductility with residual stress — stress relief is normally mandatory. | 1,450 | 1,750 | 3 | 52 HRC | — |
What is H11?
Vacuum-melted, vanadium-modified 5%Cr hot-work tool steel used in aerospace for high-strength structural forgings such as landing gear and rocket motor components, valued for hardenability and toughness at ~1900MPa. H11 has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,427°C (2,601 °F). H11 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 65% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
What is H11 used for?
- Die casting dies and inserts
- Forging dies
- Aerospace landing gear forgings
- Rocket motor structural components
- Hot extrusion dies and mandrels
- Hot shear blades and punches
- High-strength structural fittings
Advantages
- Polishes to a fine finish — 75/100, better than 94% of steel grades
- High service temperature — 540°C (1,004 °F), better than 93% of steel grades
Limitations
- Poor heat conductor — 25 W/m·K (14.4 BTU/hr·ft·°F), worse than 88% 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
H11 properties
Typical room-temperature values for H11-Annealed; bars are the position among steel grades.
Physical3
H11 has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,427°C (2,601 °F).
Mechanical13
H11 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 65% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
H11 is rated for continuous service to 540°C (1,004 °F). It conducts heat at 25 W/m·K (14.4 BTU/hr·ft·°F), worse than 88% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
H11 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 H11 takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 40%.
Manufacturability8
H11's machinability is good (55/100, better than 62% of steel grades); weldability fair (35/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. H11 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with H11
Is H11 easy to machine?
Machine in the annealed state (≈200 HB) with rigid setups and coated carbide; hardened 46–52 HRC parts need ceramic/CBN, EDM or grinding, and EDM white layer must be stoned or stress-relieved off.
Can H11 be welded?
Repair-weldable with matched 1.2343/H11 filler at 300–450 °C preheat, small stringer beads, then temper 20–30 °C below the last tempering temperature; never weld cold.
Can H11 be formed, bent or molded?
Hot work only — forge 1050–1100 °C, stop above 900 °C and cool slowly, then spheroidize anneal at 750–800 °C; cold forming is not practical.
Manufacturability
The process limits FabDigit's quote engine applies to H11. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Fair55 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
H11 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 |
|---|---|---|
| C1.2343: 0.36–0.42 | 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 |
| Mo1.2343: 1.10–1.40 | 1.1 – 1.6 | 1.3 |
| V1.2343: 0.25–0.50 | 0.3 – 0.6 | 0.4 |
| Niresidual | ≤ 0.3 | |
| Curesidual | ≤ 0.25 | |
| Wresidual | ≤ 0.3 | |
| P | ≤ 0.03 | |
| Smax; premium ESR ≤0.005 | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on H11?
Vacuum-harden and double/triple temper above 550 °C for dimensional stability, then nitride, PVD-coat (CrN/AlCrN) or hard-chrome for wear and soldering resistance; ESR grades polish to a mirror/photo-etch finish.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel H11 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T20811
- ASTM
- A681
- EN / DIN / Werkstoff-Nr.
- 1.2343
- GB (China)
- 4Cr5MoSiV14Cr5MoSiV
How much does H11 cost?
H11 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
H11 — frequently asked
What is H11 used for?
H11 is typically used for die casting dies and inserts, forging dies, aerospace landing gear forgings, rocket motor structural components, hot extrusion dies and mandrels and hot shear blades and punches. In short: hot-work tool steel.
What is the yield strength of H11?
H11 has a typical yield strength of 510 MPa (74 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 65% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is H11 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine in the annealed state (≈200 HB) with rigid setups and coated carbide; hardened 46–52 HRC parts need ceramic/CBN, EDM or grinding, and EDM white layer must be stoned or stress-relieved off.
Can H11 be welded?
With care — weldability is rated fair (35/100). Repair-weldable with matched 1.2343/H11 filler at 300–450 °C preheat, small stringer beads, then temper 20–30 °C below the last tempering temperature; never weld cold.
What surface finishes work on H11?
Vacuum-harden and double/triple temper above 550 °C for dimensional stability, then nitride, PVD-coat (CrN/AlCrN) or hard-chrome for wear and soldering resistance; ESR grades polish to a mirror/photo-etch finish.
Can H11 be formed, bent or molded?
Hot work only — forge 1050–1100 °C, stop above 900 °C and cool slowly, then spheroidize anneal at 750–800 °C; cold forming is not practical.
What is the maximum service temperature of H11?
H11 is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between H11 Annealed and H11-HIP?
Annealed is the default condition — standard mill-supply state for bar/plate that will be machined then hardened by the toolmaker. HIP: use for AM or PM tooling where residual porosity must be closed; gives near-wrought toughness and isotropic properties. Yield strength is 510 MPa in Annealed versus 1,400 MPa in HIP.
How much does H11 cost?
H11 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in H11?
Yes — H11 is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A681 — Standard Specification for Tool Steels Alloy — ASTM International (2022)
- EN ISO 4957 — Tool steels (1.2343 / X37CrMoV5-1) — CEN/ISO (2018)
- GB/T 1299 — (4Cr5MoSiV) — SAC (2014)
- ASM Handbook Vol.1: Properties and Selection — Tool Steels — ASM International (1990)
- Tool Steels, 5th ed. (Roberts, Krauss, Kennedy) — ASM International (1998)
- BÖHLER W300 / W302 hot work tool steel data sheet — voestalpine BÖHLER Edelstahl (2022)
- Uddeholm hot-work tool steel technical data (5%Cr grades) — Uddeholm/voestalpine (2021)
- MMPDS aircraft-quality H11 (5Cr-Mo-V) ultra-high-strength steel data — Battelle/FAA (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.