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Hardox 400

Hardox 400 β€” quenched abrasion-resistant steel plate 370-430 HB. Standard for dump truck bodies, excavator buckets, crusher liners and conveyor chutes.

Structural Steels Wear-Resistant Steel SSAB Trade NameHardox 400 EN 10029Quenched wear-resistant plate, ~HB 400 class ASTMA514 Grade B (nearest structural; lower hardness) JISNM400 (nearest wear plate class) +8
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Description

Hardox 400 per SSAB specification (similar EN 10029 quenched wear plate). Quenched high-hardness plate with guaranteed hardness 370-430 HB achieved through low-carbon Ni-Cr-Mo-B chemistry and water quenching. Outstanding impact and abrasion resistance. Through-hardened in thicknesses 4-160 mm. Industry standard for dump truck bodies, excavator attachments and mining wear applications.

Key Properties β€” As Delivered β€” Q+T
Rm (Tensile Strength)
1,250
MPa
Re / Rp0.2 (Yield)
1,000
MPa
Aβ‚… (Elongation)
β‰₯ 10.0
%
Hardness
370 – 430
HB
E (Young's Modulus)
210
GPa
Density
7.85
g/cmΒ³
Main Designations (12)
Standard BodyDesignationCountry / RegionNote
SSAB Trade Name Hardox 400 Global (SSAB AB) Defined by SSAB product spec
EN 10029 Quenched wear-resistant plate, ~HB 400 class European Union No direct EN designation for this hardness class
ASTM A514 Grade B (nearest structural; lower hardness) USA Similar Q procedure; Hardox is harder
JIS NM400 (nearest wear plate class) Japan
GOST Schit-500 (nearest) Russia / CIS
COMPARABLE Raex 400 (SSAB Ruukki) / Quard 400 (NLMK) / Durostat 400 (ThyssenKrupp) Global Alternative wear plate brands at HB 400 class
GB NM400 China Chinese equivalent wear plate
JUS No direct equivalent β€” exceeds JUS hardness classes Yugoslavia / Serbia
Trade Name Hardox 400 (SSAB) -- the global reference wear plate standard Global (SSAB)
Comparable Raex 400 (SSAB) / XAR 400 (ThyssenKrupp) / Quard 400 (NLMK) / Creusabro 4000 (Industeel) Global
ASTM (nearest) A514 / A517 (similar strength, different spec) USA
JUS Nema direktnog; abrazivni habajuci celik Yugoslavia/BiH Hardox 400 limovi za habanje
Standards (12)
#Standard BodyDesignationCountry / RegionNote
1 SSAB Trade Name Hardox 400 Global (SSAB AB) Defined by SSAB product spec
2 EN 10029 Quenched wear-resistant plate, ~HB 400 class European Union No direct EN designation for this hardness class
3 ASTM A514 Grade B (nearest structural; lower hardness) USA Similar Q procedure; Hardox is harder
4 JIS NM400 (nearest wear plate class) Japan β€”
5 GOST Schit-500 (nearest) Russia / CIS β€”
6 COMPARABLE Raex 400 (SSAB Ruukki) / Quard 400 (NLMK) / Durostat 400 (ThyssenKrupp) Global Alternative wear plate brands at HB 400 class
7 GB NM400 China Chinese equivalent wear plate
8 JUS No direct equivalent β€” exceeds JUS hardness classes Yugoslavia / Serbia β€”
9 Trade Name Hardox 400 (SSAB) -- the global reference wear plate standard Global (SSAB) β€”
10 Comparable Raex 400 (SSAB) / XAR 400 (ThyssenKrupp) / Quard 400 (NLMK) / Creusabro 4000 (Industeel) Global β€”
11 ASTM (nearest) A514 / A517 (similar strength, different spec) USA β€”
12 JUS Nema direktnog; abrazivni habajuci celik Yugoslavia/BiH Hardox 400 limovi za habanje
All values in wt.%
C
Carbon
≀ 0.3200
Si
Silicon
≀ 0.7000
Mn
Manganese
≀ 1.6000
P
Phosphorus
≀ 0.0250
S
Sulphur
≀ 0.0100
Cr
Chromium
≀ 1.0000
Ni
Nickel
≀ 1.0000
Mo
Molybdenum
≀ 0.5000
B
Boron
≀ 0.0050
ElementSymbolMin %Max %Typical %
Carbon C β€” 0.3200 0.2200
Silicon Si β€” 0.7000 0.4000
Manganese Mn β€” 1.6000 1.1000
Phosphorus P β€” 0.0250 β€”
Sulphur S β€” 0.0100 β€”
Chromium Cr β€” 1.0000 0.4000
Nickel Ni β€” 1.0000 0.3000
Molybdenum Mo β€” 0.5000 0.2000
Boron B β€” 0.0050 0.0020
Mechanical Properties
ConditionCode Rm min
MPa		Rm max
MPa		 Re min
MPa		Re max
MPa		 Aβ‚… min
%		 Z
%		 KV
J		 HB minHB max HRC minHRC max E
GPa
As Delivered β€” Q+T Q+T 1,250 β€” 1,000 β€” 10.0 β€” β€” 370 430 β€” β€” 210.0
Physical Properties
Density
7.850
g/cmΒ³
Melting Point
1485–1520
Β°C
Young's Modulus
210.0
GPa
Poisson's Ratio
0.295
β€”
Thermal Conductivity
38.0
W/mΒ·K
Thermal Expansion
12.00
Γ—10⁻⁢ /K
Specific Heat
490
J/kgΒ·K
Electrical Resistivity
0.2700
¡Ω·m
Magnetic
Yes
 
Heat Treatment
Stress Relieving (if required)
Temperature:550Β°C – 600Β°C
Medium:Furnace
Duration:1h per 25mm
Cooling:<=200 C/h
Hardness After:Slight drop in HB
Slight softening occurs β€” confirm with SSAB. Generally avoided.
Bending (cold)
Medium:Cold bending only
Duration:Minimum bend radius per SSAB table
Cooling:-
Minimum bend radius varies with thickness β€” always consult SSAB bending guide.
Machinability
Machinability Rating
relative to AISI B1112 = 100%
35.0%
Very Difficult
Turning Speed (HSS)
18
m/min
Turning Speed (Carbide)
110
m/min
Feed Rate (Turning)
0.140
mm/rev
Drilling Speed (HSS)
12
m/min
Milling Speed (Carbide)
115
m/min
CoolantSoluble oil 8-12%; high-pressure recommended
Chip FormationShort brittle chips; high cutting forces
Tool MaterialCarbide P10/P15 TiAlN coated; CBN for hardened condition; plasma cutting for profiling
Surface FinishRa 0.8-3.2 um
Hard to machine β€” cutting forces 2-3x S355. Carbide only. Plasma or laser cutting preferred for profiling. Drilling requires TiAlN-coated or solid carbide drills.
Applications
Mining & Quarrying
Dump truck bodies, haul truck bodies, mining buckets and crusher wear plates.
Earthmoving
Excavator buckets, dipper sticks, wear liners and dozer blades.
Recycling & Crushing
Crusher liners, jaw plates, hammer mill liners and impact plates.
Bulk Material Handling
Conveyor chutes, hopper liners, silo walls and truck bodies for abrasive bulk materials.
Dump Trucks
Payload body liners, floor plates and side walls of off-road dump trucks.
Excavators
Excavator bucket floors, side walls and cutting edges.
Crushing and Screening
Fixed jaw plates, side liners and impact bars in aggregate crushing plants.
Chutes and Hoppers
Material transfer chutes, hoppers and silos for abrasive bulk solids.
Technical Notes
βœ…
Weight Saving vs S355
Hardox 400 is 2-3x harder than S355 but same density. Using Hardox instead of S355 for wear applications allows 50-60% reduction in material thickness for the same wear life, reducing vehicle payload weight.
πŸ”₯
Weldability
Requires care. Pre-heat 50-100 C for sections >8 mm. Use low-hydrogen electrodes (E690 or E890 class). Avoid high heat input. Consult SSAB weld guidelines (Hardox Weldability).
⚠️
Cutting Temperature
Plasma, laser and oxyfuel cutting create a HAZ that reduces hardness in a narrow zone. Re-hardening of cut edges is generally not practical in field β€” design to allow for HAZ.
πŸ’‘
The Global Wear Plate Standard
Hardox 400 (SSAB) is the most recognised wear plate brand globally and the de facto industry reference. Approximately 60 Hardox grades and variants exist; 400 is the most widely specified general-purpose grade. The Hardox brand is used generically even for competitor wear plates in the industry.
βœ…
Hardox grade selection
Hardox 400 (HBW 370-430): standard abrasion. Hardox 450 (HBW 425-475): 15% better wear life. Hardox 500 (HBW 470-540): 30% better wear life. Hardox 600 (HBW 570-640): maximum hardness, limited toughness. Upgrade to next grade when wear life increase justifies cost premium.