Steel H19
AISI/SAE H19 · UNS T20819
H19 is a cobalt-bearing chromium-tungsten hot-work tool steel (UNS T20819, AISI H-group) that gives the highest hot hardness and red-hardness of the H10–H19 chromium series, at some cost to toughness.
Reference datasheet — H19 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the ANN condition
H19 tempers and conditions
H19 is supplied in 5 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard stock condition for bar and block: soft enough for rough machining before hardening. | 520 | 800 | 18 | 20 HRC | — |
Hardened & tempered 44–48 HRC | Pick for hot forging dies and extrusion tooling where thermal-fatigue cracking, not wear, is the failure mode. | 1,300 | 1,500 | 10 | 46 HRC | — |
Hardened & tempered 50–52 HRC | The usual delivered working condition: austenitize ~1150–1200 °C, quench, double temper ~590–620 °C for best hot hardness/toughness balance. | 1,520 | 1,750 | 8 | 51 HRC | 25 W/m·K |
Hardened, tempered and gas/plasma nitrided | Surface-engineered condition for die-casting and extrusion inserts needing washout/soldering resistance over a 50–52 HRC core. | 1,520 | 1,750 | 7 | 51 HRC | — |
Hardened & tempered 54–57 HRC | Choose for hot punches, shear blades and hot-work tools where abrasion and hot compressive strength dominate and impact loading is low. | 1,720 | 1,980 | 5 | 55 HRC | — |
What is H19?
H19 is a cobalt-bearing chromium-tungsten hot-work tool steel (UNS T20819, AISI H-group) that gives the highest hot hardness and red-hardness of the H10–H19 chromium series, at some cost to toughness. It is stocked as annealed bar, plate and forged blocks and run in the QT44-48, QT50-52 or QT54-57 hardened conditions, often with a nitrided (NIT) working face. Annealed values are 520 MPa yield, 800 MPa tensile, 18 % elongation and 220 HB, with a 400 °C maximum service temperature in that state and low corrosion resistance (score 15). Where impact toughness matters more than red hardness, H13 is the usual substitute. H19 has a density of 8.19 g/cm³ (0.296 lb/in³), heavier than 98% of steel grades. It melts at 1,370°C (2,498 °F). H19 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 67% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
What is H19 used for?
- Hot extrusion tooling
- Hot shear blades
- Piercer points
- High-temperature forging dies
Limitations
- Low electrical conductivity — 2.7 % IACS, worse than 96% of steel grades
- High embodied carbon — 3.2 kg CO₂/kg, worse than 92% of steel grades
- Poor heat conductor — 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades
- Difficult to machine — 35/100, worse than 84% of steel grades
H19 properties
Typical room-temperature values for H19-ANN; bars are the position among steel grades.
Physical3
H19 has a density of 8.19 g/cm³ (0.296 lb/in³), heavier than 98% of steel grades. It melts at 1,370°C (2,498 °F).
Mechanical16
H19 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 67% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
H19 is rated for continuous service to 400°C (752 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades. Thermal expansion is 11.2 µm/m·K (6.22 µin/in·°F).
Electrical3
H19 conducts electricity at 2.7 % IACS, worse than 96% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of H19 takes about 45 MJ of energy and emits 3.2 kg of CO₂ — more than 93% of steel grades. Typical recycled content is 40%.
Manufacturability8
H19's machinability is fair (35/100, worse than 84% of steel grades); weldability poor (30/100); formability poor (25/100).
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. H19 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with H19
Is H19 easy to machine?
Machine only in the annealed state with rigid setups, sharp carbide or coated carbide at reduced speed — the W/V carbides are abrasive and tool life is roughly a third of 4140; finish hardened parts by grinding or EDM (re-temper after EDM).
Can H19 be welded?
Repair-weld with matching hot-work filler at 400–500 °C preheat, maintain interpass temperature, and temper immediately at ~25 °C below the last tempering temperature to avoid cracking.
Can H19 be formed, bent or molded?
Hot work at 1050–1150 °C, never below ~900 °C, then slow-cool and fully anneal at ~870–900 °C; cold forming is not practical.
H19 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 | 0.32 – 0.45 | 0.4 |
| Mn | 0.2 – 0.5 | 0.3 |
| Si | 0.2 – 0.5 | 0.3 |
| Cr | 4 – 4.75 | 4.25 |
| W | 3.75 – 4.5 | 4.25 |
| Cogives the red-hardness advantage over H10–H13 | 4 – 4.5 | 4.25 |
| V | 1.75 – 2.2 | 2 |
| Mo | 0.3 – 0.55 | 0.4 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on H19?
Not anodizable; use nitriding, oxidizing/blackening, or PVD CrN/AlTiN on the tempered surface, and keep tempering above the coating deposition temperature to avoid softening.
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).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel H19 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T20819
How much does H19 cost?
H19 is a high-cost steel ($$$$), pricier than about 78% 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.
H19 — frequently asked
What is H19 used for?
H19 is typically used for hot extrusion tooling, hot shear blades, piercer points and high-temperature forging dies. In short: highest red hardness in H10–H19; cobalt-alloyed hot-work grade; tougher alternative is H13.
What is the yield strength of H19?
H19 has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 67% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is H19 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Machine only in the annealed state with rigid setups, sharp carbide or coated carbide at reduced speed — the W/V carbides are abrasive and tool life is roughly a third of 4140; finish hardened parts by grinding or EDM (re-temper after EDM).
Can H19 be welded?
Not readily — weldability is rated poor (30/100). Repair-weld with matching hot-work filler at 400–500 °C preheat, maintain interpass temperature, and temper immediately at ~25 °C below the last tempering temperature to avoid cracking.
What surface finishes work on H19?
Not anodizable; use nitriding, oxidizing/blackening, or PVD CrN/AlTiN on the tempered surface, and keep tempering above the coating deposition temperature to avoid softening.
Can H19 be formed, bent or molded?
Hot work at 1050–1150 °C, never below ~900 °C, then slow-cool and fully anneal at ~870–900 °C; cold forming is not practical.
What is the maximum service temperature of H19?
H19 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between H19-ANN and H19 QT54-57?
ANN is the default condition — standard stock condition for bar and block: soft enough for rough machining before hardening. QT54-57: choose for hot punches, shear blades and hot-work tools where abrasion and hot compressive strength dominate and impact loading is low. Yield strength is 520 MPa in ANN versus 1,720 MPa in QT54-57.
How much does H19 cost?
H19 is a high-cost steel ($$$$), pricier than about 78% 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.
Sources
- ASTM A681 — Standard Specification for Tool Steels Alloy — ASTM International (2022)
- SAE AMS 6455 / UNS T20819 designation data — SAE International (2020)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys (Hot-Work Tool Steels) — ASM International (1990)
- ASM Handbook Vol.16: Machining (machinability ratings of tool steels) — ASM International (1989)
- Tool Steels, 5th Edition (Roberts, Krauss, Kennedy) — ASM International (1998)
- Hot-work tool steel heat-treatment and property bulletins — Böhler / Crucible / Carpenter (2022)
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.