Hardox 400 Steel
An abrasion-resistant (AR) steel, 400 HBW
Typical values for the temper in the title
Hardox 400 is an SSAB trade name for a quenched and tempered, abrasion-resistant plate steel, with a nominal hardness of 400 HBW (range 370–430). The high hardness gives good resistance to wear from sand, rock and abrasive materials, and the steel is still tough enough to be bent and welded.
It is used for truck bodies, buckets, chutes, crushers and wear liners. Similar steels from other producers are named by hardness (AR400, NM400 and so on).
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 1250 MPa | database value |
| Yield strength Rp0.2 | 1000 MPa | database value |
| Elongation A | 10% | |
| Hardness | 370-430 HB | range per SSAB |
| Modulus of elasticity E | 210 GPa | |
| Density ρ | 7.85 g/cm³ | |
| Machinability | 30% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| C carbon | low-medium (per SSAB, varies with thickness) | hardness |
| Cr / Ni / Mo / B | per SSAB | hardenability |
| Fe iron | balance |
Composition per the SSAB data sheet, and varies with thickness.
Conditions and heat treatment
Structural, pressure and pipeline steels are selected by minimum yield strength and impact toughness at a given temperature, not by a heat treatment the user performs. The delivery condition is defined by the standard.
| Condition | Properties | When to choose it |
|---|---|---|
| Quenched and tempered | 370–430 HBW | delivery condition |
Applications
- Truck and mining truck bodies
- Buckets and teeth for equipment
- Chutes and channels for abrasive materials
- Crushers and grinders
- Wear liners
Fabrication
Machining
Possible with carbide tools, at low speed and with rigid fixturing.
Bending
Possible, with a larger bend radius than ordinary steel (per SSAB tables).
Welding
Possible with preheat by thickness, and relatively low-strength filler. Do not heat above the tempering temperature, to avoid losing hardness.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| S690QL | 760-940 / 690 MPa | Difficult — Preheat mandatory | a high-strength structural steel, for load bearing · material page |
| D2 | 800 MPa anneal / — | Not recommended | a tool steel, much harder · material page |
| 1045 | 570–700 / 310–450 MPa | Medium | a carbon steel, much softer · material page |
Common mistakes
Using Hardox as a load-bearing steel in calculations
It is meant for wear. For strength calculations use producer data or a structural steel.
Flame cutting thick plate without preheat
Risk of edge cracking.
Heating for straightening
Heat reduces hardness.
Equivalents, standards and supply
| Standards | SSAB (producer specification) |
|---|---|
| Forms | plate 3-130mm |
| Producers | SSAB |
Learn more
Values are typical and for comparison only, and depend strongly on condition and diameter. For design, rely on the standard and on the mill certificate. Sources: SAE J403 and J404, ASTM A29, A322 and A519 (composition), producer data sheets, and the METAL HUB materials database.
Updated: October 31, 2026