Steel Hardox 400 Q&T THICK
Heat-treated state
GB NM400
Heavy-gauge Q&T plate for crusher parts and large wear blocks; needs higher preheat when welding and shows slightly lower core hardness.
Values for the Q&T THICK condition
Other Hardox 400 tempers and conditions
Hardox 400 is listed in 3 conditions; see the grade overview at Hardox 400.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Q&T THICKThis page Quenched & Tempered, higher CEV | Heavy-gauge Q&T plate for crusher parts and large wear blocks; needs higher preheat when welding and shows slightly lower core hardness. | 950 | 1,200 | 10 | 42 HRC | 7 % IACS |
Q&TDefault Quenched and tempered | Standard as-delivered Hardox 400 plate condition for all abrasion-resistant applications. | 1,000 | 1,250 | 10 | 43 HRC | — |
Quenched & Tempered, guaranteed 45 J at -40 °C | Thin-gauge Q&T plate/coil for liners, chutes and cold-bent wear parts where formability and full toughness are needed. | 1,000 | 1,250 | 11 | 43 HRC | 7 % IACS |
What is Hardox 400 Q&T THICK?
Hardox 400 Q&T THICK is Hardox 400 heat treated to Q&T THICK — heavy-gauge Q&T plate for crusher parts and large wear blocks; needs higher preheat when welding and shows slightly lower core hardness. Hardox 400 Q&T THICK has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,200 MPa (174 ksi) — stronger than 91% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). Hardox 400 Q&T THICK 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). Q&T is the default condition FabDigit quotes; Q&T THICK is available on request or by drawing note.
Advantages
- High strength — 950 MPa (138 ksi), better than 91% of steel grades
Limitations
- Difficult to machine — 27/100, worse than 92% 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 THICK properties
Typical room-temperature values for Hardox 400 Q&T THICK; 22 are specific to this condition. Other listed values are Hardox 400 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
Hardox 400 Q&T THICK 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 THICK has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,200 MPa (174 ksi) — stronger than 91% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
Hardox 400 Q&T THICK 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 THICK 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 THICK takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability6
Hardox 400 Q&T THICK's machinability is poor (27/100, worse than 92% of steel grades); weldability fair (50/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Hardox 400 Q&T THICK
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 THICK — frequently asked
What is Hardox 400 Q&T THICK used for?
Hardox 400 Q&T THICK 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 THICK?
Hardox 400 Q&T THICK has a typical yield strength of 950 MPa (138 ksi) and a tensile strength of 1,200 MPa (174 ksi) — stronger than 91% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is Hardox 400 Q&T THICK easy to machine?
Not especially — machinability is rated poor (27/100, worse than 92% 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 THICK be welded?
With care — weldability is rated fair (50/100). 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 THICK?
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 THICK 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 THICK?
Hardox 400 Q&T THICK 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 THICK?
Yes — Hardox 400 Q&T THICK is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. 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.