Steel Hardox 400 · heat-treated state · default condition
Steel Hardox 400 Q&T
Properties of the Q&T condition, compared with the other Hardox 400 tempers.
Standard as-delivered Hardox 400 plate condition for all abrasion-resistant applications.
What is Hardox 400 Q&T?
Hardox 400 Q&T is Hardox 400 heat treated to Q&T — standard as-delivered Hardox 400 plate condition for all abrasion-resistant applications. Hardox 400 Q&T has a yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,250 MPa (181 ksi) — stronger than 92% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). Hardox 400 Q&T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Advantages
- High strength — 1,000 MPa (145 ksi), better than 92% of steel grades
Limitations
- Difficult to machine — 25/100, worse than 93% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades
Hardox 400 Q&T properties
Typical room-temperature values for Hardox 400 Q&T — 11 properties are specific to this condition; the rest are grade-level values shared by every Hardox 400 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
Hardox 400 Q&T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
Hardox 400 Q&T has a yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,250 MPa (181 ksi) — stronger than 92% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
Hardox 400 Q&T is rated for continuous service to 250°C (482 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
Hardox 400 Q&T conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of Hardox 400 Q&T takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 55% of steel grades. Typical recycled content is 25%.
Manufacturability6
Hardox 400 Q&T's machinability is poor (25/100, worse than 93% of steel grades); weldability good (60/100); formability fair (40/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Hardox 400 tempers and conditions
Hardox 400 is also supplied in 2 other conditions. The full side-by-side table is on the Hardox 400 overview.
- Q&TDefaultStandard as-delivered Hardox 400 plate condition for all abrasion-resistant applications.1,000 MPa yield · 43 HRC
- Q&T THICKHeavy-gauge Q&T plate for crusher parts and large wear blocks; needs higher preheat when welding and shows slightly lower core hardness.950 MPa yield · 390 HB
Working with Hardox 400 Q&T
Is Hardox 400 easy to machine?
Machinable with rigid setups, coated carbide and reduced speeds/feeds; drilling needs low rpm and high feed pressure — plasma/laser/waterjet cutting is usually preferred over milling.
Can Hardox 400 be welded?
Good weldability with low-hydrogen consumables (soft or matching), preheat 75–150 °C depending on thickness and joint restraint; keep heat input low to limit HAZ softening.
Can Hardox 400 be formed, bent or molded?
Cold bendable transverse to rolling direction with generous inside radii (≈3–4× t) and press-brake dies sized for 1000 MPa yield; hot forming above 250 °C destroys the temper.
What surface finishes work on Hardox 400?
Shot-blast and paint or zinc-rich prime for corrosion protection; hardfacing overlays can be applied where wear exceeds base-plate life.
Hardox 400 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 |
|---|---|---|
| Cmax depends on thickness (0.15 % thin – 0.32 % thick) | ≤ 0.32 | 0.16 |
| Si | ≤ 0.7 | 0.3 |
| Mn | ≤ 1.6 | 1.2 |
| P | ≤ 0.03 | — |
| S | ≤ 0.01 | — |
| Crhardenability addition, thickness dependent | ≤ 1.4 | 0.5 |
| Nithickness dependent | ≤ 1.5 | 0.25 |
| Mothickness dependent | ≤ 0.6 | 0.15 |
| Bboron for hardenability | ≤ 0.01 | 0 |
| Fe | balance | — |
Hardox 400 Q&T — frequently asked
What is Hardox 400 Q&T used for?
Hardox 400 Q&T is typically used for excavator and loader bucket liners, mining shovel wear parts, dump-body and chute liners, crusher and screen wear plates, conveyor skirt and scraper blades and dozer blade cutting edges. In short: workhorse abrasion wear plate.
What is the yield strength of Hardox 400 Q&T?
Hardox 400 Q&T has a typical yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,250 MPa (181 ksi) — stronger than 92% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is Hardox 400 Q&T easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% of steel grades). Machinable with rigid setups, coated carbide and reduced speeds/feeds; drilling needs low rpm and high feed pressure — plasma/laser/waterjet cutting is usually preferred over milling.
Can Hardox 400 Q&T be welded?
Yes — weldability is rated good (60/100). Good weldability with low-hydrogen consumables (soft or matching), preheat 75–150 °C depending on thickness and joint restraint; keep heat input low to limit HAZ softening.
What surface finishes work on Hardox 400 Q&T?
Shot-blast and paint or zinc-rich prime for corrosion protection; hardfacing overlays can be applied where wear exceeds base-plate life.
Can Hardox 400 Q&T be formed, bent or molded?
Cold bendable transverse to rolling direction with generous inside radii (≈3–4× t) and press-brake dies sized for 1000 MPa yield; hot forming above 250 °C destroys the temper.
What is the maximum service temperature of Hardox 400 Q&T?
Hardox 400 Q&T is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in Hardox 400 Q&T?
Yes — Hardox 400 Q&T is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Hardox 400 — Data Sheet, abrasion-resistant steel plate — SSAB (2024)
- Welding and cutting of Hardox / WearCalc guidance — SSAB (2023)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASTM E140 — Standard Hardness Conversion Tables for Metals — ASTM (2019)
- GB/T 24186 — (NM400 comparison) — SAC (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.