Steel H21 · hardness band
Steel H21 Q&T 44-48 HRC
Properties of the Q&T 44-48 HRC condition, compared with the other H21 tempers.
Most common working hardness for hot extrusion dies, punches and brass die-casting inserts.
What is H21 Q&T 44-48 HRC?
H21 Q&T 44-48 HRC is H21 heat treated to Q&T 44-48 HRC — most common working hardness for hot extrusion dies, punches and brass die-casting inserts. H21 Q&T 44-48 HRC has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 95% of steel grades. Elongation at break is 9% and the elastic modulus is 210 GPa (30.5 Msi). H21 Q&T 44-48 HRC has a density of 8.28 g/cm³ (0.299 lb/in³), heavier than 98% of steel grades. It melts at 1,420°C (2,588 °F). Annealed is the default condition FabDigit quotes; Q&T 44-48 HRC is available on request or by drawing note.
Advantages
- High service temperature — 610°C (1,130 °F), better than 99% of steel grades
- High strength — 1,350 MPa (196 ksi), better than 95% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited ductility — 9%, worse than 93% of steel grades
- High embodied carbon — 3 kg CO₂/kg, worse than 91% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
- Poor heat conductor — 27 W/m·K (15.6 BTU/hr·ft·°F), worse than 85% of steel grades
- Difficult to weld — 25/100, worse than 77% of steel grades
H21 Q&T 44-48 HRC properties
Typical room-temperature values for H21 Q&T 44-48 HRC — 8 properties are specific to this condition; the rest are grade-level values shared by every H21 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
H21 Q&T 44-48 HRC has a density of 8.28 g/cm³ (0.299 lb/in³), heavier than 98% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical14
H21 Q&T 44-48 HRC has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 95% of steel grades. Elongation at break is 9% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
H21 Q&T 44-48 HRC is rated for continuous service to 610°C (1,130 °F). It conducts heat at 27 W/m·K (15.6 BTU/hr·ft·°F), worse than 85% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical2
H21 Q&T 44-48 HRC has an electrical resistivity of 5.5×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of H21 Q&T 44-48 HRC takes about 42 MJ of energy and emits 3 kg of CO₂ — more than 91% of steel grades. Typical recycled content is 45%.
Manufacturability8
H21 Q&T 44-48 HRC's machinability is fair (40/100, worse than 76% of steel grades); weldability poor (25/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other H21 tempers and conditions
H21 is also supplied in 7 other conditions. The full side-by-side table is on the H21 overview.
- AnnealedDefaultStandard stock condition for machining dies and inserts before hardening.620 MPa yield · 220 HB
- Q&T 50-54 HRCChoose for hot shear blades and small punches where abrasive hot wear dominates and shock is low.1,600 MPa yield · 52 HRC
- Q&TGeneral hardened-and-tempered service condition for hot dies at 45–52 HRC.1,450 MPa yield · 49 HRC
- Hardened & TemperedDouble-tempered condition specified when maximum thermal-fatigue and softening resistance is required.1,350 MPa yield · 47 HRC
- Q&T 44-48 HRCMost common working hardness for hot extrusion dies, punches and brass die-casting inserts.1,350 MPa yield · 46 HRC
- Q&T 38-42 HRCPick for large hot-forging dies and dummy blocks where gross cracking, not wear, is the failure mode.1,100 MPa yield · 40 HRC
Working with H21 Q&T 44-48 HRC
Is H21 easy to machine?
Machine only in the annealed condition (≤241 HB) with rigid setups and coated carbide; tungsten carbides are abrasive so keep speeds moderate, and finish-grind after hardening.
Can H21 be welded?
Repair welding only: preheat 400–500 °C, matching W-alloy or H13-type filler, weld hot and temper immediately below the last tempering temperature to avoid cracking.
Can H21 be formed, bent or molded?
Hot work at 1050–1150 °C with slow furnace cooling and mandatory soft anneal (~870 °C, slow cool) afterwards; no meaningful cold formability.
What surface finishes work on H21?
Takes a good polish when hardened; protect with oiling, phosphate, nitriding or PVD/chromizing since bare surfaces rust and suffer hot washout.
H21 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 | 0.26 – 0.36 | 0.31 |
| Si | 0.15 – 0.5 | 0.3 |
| Mn | 0.15 – 0.4 | 0.3 |
| Cr | 3 – 3.75 | 3.4 |
| Wprimary hot-hardness element | 8.5 – 10 | 9.25 |
| V | 0.3 – 0.6 | 0.45 |
| Moresidual / optional | ≤ 0.5 | — |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.25 | — |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
H21 Q&T 44-48 HRC — frequently asked
What is H21 Q&T 44-48 HRC used for?
H21 Q&T 44-48 HRC is typically used for brass and copper-alloy extrusion dies, hot punches and piercing points, hot forging die inserts, hot shear blades, extrusion mandrels and dummy blocks and die-casting dies for copper alloys. In short: hot-work tool steel.
What is the yield strength of H21 Q&T 44-48 HRC?
H21 Q&T 44-48 HRC has a typical yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is H21 Q&T 44-48 HRC easy to machine?
Not especially — machinability is rated fair (40/100, worse than 76% of steel grades). Machine only in the annealed condition (≤241 HB) with rigid setups and coated carbide; tungsten carbides are abrasive so keep speeds moderate, and finish-grind after hardening.
Can H21 Q&T 44-48 HRC be welded?
Not readily — weldability is rated poor (25/100). Repair welding only: preheat 400–500 °C, matching W-alloy or H13-type filler, weld hot and temper immediately below the last tempering temperature to avoid cracking.
What surface finishes work on H21 Q&T 44-48 HRC?
Takes a good polish when hardened; protect with oiling, phosphate, nitriding or PVD/chromizing since bare surfaces rust and suffer hot washout.
Can H21 Q&T 44-48 HRC be formed, bent or molded?
Hot work at 1050–1150 °C with slow furnace cooling and mandatory soft anneal (~870 °C, slow cool) afterwards; no meaningful cold formability.
What is the maximum service temperature of H21 Q&T 44-48 HRC?
H21 Q&T 44-48 HRC is rated for continuous use to about 610°C (1,130 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in H21 Q&T 44-48 HRC?
Yes — H21 Q&T 44-48 HRC 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 (2015)
- GB/T 1299 (3Cr2W8V) — SAC (2014)
- ASM Handbook Vol.1 – Properties and Selection: Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- Tool Steels, 5th ed. (Roberts, Krauss, Kennedy) — ASM International (1998)
- X30WCrV9-3 / 1.2581 hot-work tool steel datasheet — Böhler / Ovako-class producers (2020)
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.