Wear-Resistant Steel Plates
Marked to standard
Standard, grade, dimensions and heat number inkjet-marked on the plate at the mill.
Wear-Resistant Steel Plates
NM400 Wear-Resistant Steel Plate
Product Overview
NM400 is the most widely specified grade of the Chinese wear-resistant plate series and is produced to GB/T 24186-2022. Delivered quenched and tempered at 370 – 430 HBW, it is the grade that most buyers mean when they say “wear plate”: hard enough to multiply the service life of a liner several times over against structural steel, and still workable enough that a normal fabrication shop can cut, roll, drill and weld it with controlled preheat.
The grade sits at the balance point of the series. Below it, NM360 trades wear life for easier fabrication. Above it, NM450 and NM500 buy more abrasion resistance at the cost of forming, welding and machining effort. NM400 is where the two curves cross for most general-purpose wear work, which is why it is also the grade most commonly held in stock.
Typical users of this grade class in China are the construction and mining equipment builders, and the grade is regularly exported to Australia, Peru, Chile, Brazil and Canada — markets where the abrasion regime is aggressive and the acceptance testing is strict.
How we supply it differently: plate is sourced from first-tier Chinese mills, and can leave China cut and nested to your drawing, edge-milled, rolled or drilled, and shot blasted to Sa 2.5 with a weldable shop primer. Your workshop receives fabrication-ready parts instead of raw mill plate that still has to be blasted, cut and formed locally.
Mechanical Properties & Hardness
| Grade | Delivery | Thickness | Tensile strength Rm | Elongation A50 | Impact energy | Hardness |
|---|---|---|---|---|---|---|
| NM400E | Q + T | 6 – 150 mm | ≥ 1,200 MPa | ≥ 10 % | ≥ 24 J | 370 – 430 HBW |
Figures are the mill’s guaranteed values for NM400E/F. Tensile strength, elongation and impact energy are performance requirements: where they are not specified in the contract, only Brinell hardness is guaranteed, so state them on the order if your incoming inspection is going to test for them.
Chemical Composition (Ladle Analysis, % Max)
| Grade | C | Si | Mn | P | S | Cr | Ni | Mo | Ti | B | Als |
|---|---|---|---|---|---|---|---|---|---|---|---|
| NM400 | ≤ 0.30 | ≤ 0.7 | ≤ 1.6 | ≤ 0.025 | ≤ 0.010 | ≤ 1.2 | ≤ 0.7 | ≤ 0.50 | ≤ 0.05 | 0.0005 – 0.006 | ≥ 0.01 |
The low phosphorus and sulphur ceilings are the point of the grade: the mill’s clean-steel practice holds P at or below 40 ppm, S at or below 10 ppm and H at or below 1.2 ppm in production, which is what keeps the cold-cracking sensitivity and the brittle-to-ductile transition temperature down.
Carbon Equivalent & Weldability
| Grade | Maximum CEQ |
|---|---|
| NM360E/F | 0.56 |
| NM400E/F | 0.65 |
| NM450E/F | 0.68 |
| NM500E | 0.75 |
| NM550E | 0.78 |
| NM600E | 0.85 |
CEQ = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15. These are the mill ceilings for grades ordered to a high-weldability requirement; the actual figure for your heat is on the mill certificate.
Supply Range
| Grade | Thickness | Width | Length |
|---|---|---|---|
| NM400 | 6 – 12 mm | 1,500 – 3,000 mm | 3,000 – 15,000 mm |
| NM400 | > 12 – 150 mm | 1,500 – 4,000 mm | 3,000 – 24,000 mm |
Tighter widths and shorter lengths are available as cut-to-size or as nested parts to drawing. Longer plate than 24,000 mm is not rolled in this series.
Typical Applications
- Wide-body mining truck bodies — Body and floor panels in NM400E, supplied in widths up to 4,000 mm with a low carbon equivalent for weldability.
- Excavator and loader buckets — Cutting edges, side wear strips and bottom liner plates.
- Extra-thick bucket bottom liners — Heavy liner plate where the mill verifies by flaw detection up to 150 mm; the core hardness of 100 mm NM400 plate is held at ≥ HBW 300.
- Dump truck bodies, feeders and hoppers — General-purpose liner and wear plate on bulk handling equipment.
- Crusher feed and transfer points — Moderate impact duty, where NM450 or NM500 would be unnecessarily hard to fabricate.
Choose NM400 as the default when the wear is genuine sliding abrasion and the part still has to be fabricated.
Step up to NM450 where the abrasion is severe enough that the replacement interval, not the material price, is the cost you are managing.
Fabrication: Cutting & Forming
Cutting methods compared
| Method | Cutting speed | Kerf width | Heat-affected zone | Size tolerance |
|---|---|---|---|---|
| Oxy-fuel (flame) | 150 – 700 mm/min | 2 – 5 mm | 4 – 10 mm | ±2.0 mm |
| Plasma arc | 1,200 – 6,000 mm/min | 2 – 4 mm | 2 – 5 mm | ±1.0 mm |
| Laser | 600 – 2,200 mm/min | ≤ 1 mm | 0.4 – 3 mm | ±0.2 mm |
| Water jet | cold cutting | 0.8 – 1.2 mm | none | ±0.2 mm class |
Laser gives the tightest tolerance but the narrowest thickness window; oxy-fuel takes the widest range of thickness at the loosest tolerance; plasma sits between them. Water jet is the only method that introduces no heat at all.
Maximum flame cutting speed
| Plate thickness | NM400 | NM450 | NM500 | NM550 | NM600 |
|---|---|---|---|---|---|
| 25 mm | — | — | 300 | 270 | 260 |
| 30 mm | — | — | 250 | 230 | 220 |
| 35 mm | — | — | 230 | 190 | 180 |
| 40 mm | — | 230 | 200 | 160 | 150 |
| 45 mm | 230 | 200 | 170 | 140 | 130 |
| 50 mm | 210 | 180 | 150 | 130 | 120 |
| 60 mm | 190 | 160 | 130 | 110 | 100 |
| 70 mm | 180 | 150 | 110 | 100 | 100 |
Maximum recommended flame cutting speed in mm/min. The mill datasheet lists a ceiling only from the thickness at which preheat control becomes necessary; thinner plate is cut at higher speed.
Preheat before cutting
| Grade | Thickness requiring preheat | Preheat temperature |
|---|---|---|
| NM400 | 40 – 60 mm | 100 – 200 °C |
| NM450 | 40 – 50 mm | 100 – 200 °C |
| NM500 | 30 – 50 mm | 100 – 200 °C |
| NM550 | 20 – 50 mm | 150 – 180 °C |
| NM600 | 20 – 50 mm | 150 – 180 °C |
Preheat by flame or electric mat, and heat the cut line uniformly — local overheating is as damaging as no preheat at all. As a general rule, when the shop temperature is below 5 °C and the plate is over 20 mm, preheat before cutting regardless of grade.
- Cut clean. Mill scale, rust and oil all degrade cut quality. Clean the cut line on both faces before cutting, and clear the cutting area top and bottom.
- Tune the process, do not just run it. Nozzle size, gas pressure, cutting method and speed have to be set to the grade and thickness in front of you. Hot cutting — flame, plasma or laser — is the correct method for these grades when it is set up properly.
- Watch narrow cut-offs. Where the part being cut off is narrower than about 200 mm, the cutting heat can soften it through its width. Where that matters, use underwater plasma arc cutting, underwater laser cutting or water jet cutting — the water jet is a cold cut with no heat-affected zone and no local softening at all.
- Shearing. Plate below about 10 mm can be sheared. As the grade gets harder, shear stress and tool wear rise, so blade clearance has to be increased and the blade kept hard, sharp and slightly radiused at the corners.
- Slow cooling helps. Where cutting cracks are a concern, keeping the still-warm cut parts together and covering them so they cool slowly reduces the risk.
Fabrication: Drilling, Milling & Boring
| Hole diameter | Tool | Speed / feed |
|---|---|---|
| 10 mm | Solid carbide drill | 1,120 / 90 rpm / mm·min−1 |
| 20 mm | Solid carbide drill | 560 / 45 rpm / mm·min−1 |
| 20 mm | Replaceable carbide drill | 480 / 40 rpm / mm·min−1 |
Recommended drilling parameters for NM400, from the mill datasheet. Cool with an 8 – 10 % emulsion and keep chip evacuation smooth — chip evacuation is what governs hole quality, tool life and reliability. If the geometry allows it, use the shortest drill that will reach.
- Milling. Face milling at %s with a hard-coated carbide blade and 0.10 – 0.12 mm per tooth. Use climb milling: it makes thinner chips, puts a small tensile stress on the tool, and the downward cutting force presses the plate onto the table, so the cut is stable and tool wear is low.
- Threads. %s
- Boring. Rough bore first, then finish bore, with a hard-coated carbide blade at about 120 m/min and 0.08 mm per revolution.
- Tool life. Machining data published for wear-resistant plate assumes rigid clamping and a continuous coolant supply. If you get vibration, reduce overhang and cutting speed before you change the tool.
Welding
| Grade | ≤ 10 mm | 10 – 40 mm | > 40 mm |
|---|---|---|---|
| NM360E/F | room temperature | 20 – 75 °C | 75 – 200 °C |
| NM400E/F | room temperature | 50 – 100 °C | 100 – 200 °C |
| NM450E/F | room temperature | 75 – 125 °C | 125 – 200 °C |
| NM500E | 50 °C | 75 – 150 °C | 150 – 180 °C |
| NM550E | 50 °C | 75 – 150 °C | 100 – 150 °C |
| NM600E | 50 °C | 75 – 150 °C | 100 – 150 °C |
Minimum preheating temperature, gas-shielded welding, in °C. Preheat depends strongly on thickness, so the table is a floor, not a target.
- Groove preparation. Prepare grooves mechanically wherever possible. Where flame cutting is used, leave machining allowance and then remove the heat-affected zone and oxides by milling, planing or grinding. Narrow grooves — I type, narrow V or U — reduce filler metal and heat input; a groove angle of 30° to 50° is suggested.
- Cleanliness. Clean the groove edges and at least 50 mm either side, and grind out moisture, oil, grease and other contamination. Use a stainless steel brush or a grinding wheel.
- Dry the consumables. Stick electrodes must be dried at 300 – 350 °C for two hours before use; welding flux at 200 – 300 °C for one hour.
- Preheat properly. Whole-plate heating gives better results than local heating. Where local heating is used, the groove and the material 100 mm either side of it must all reach the specified temperature. Electric heating mats or flame heating are both acceptable.
- Why it matters. These grades have a relatively high carbon equivalent, are sensitive to hydrogen, and are prone to cold cracking and to heat-affected-zone softening. Correct preheat, correct consumables and a controlled heat input are what prevent both.
Grade Comparison: NM360 – NM600
| Grade | Hardness | Tensile Rm | Elongation A50 | Max thickness | Where it is used |
|---|---|---|---|---|---|
| NM360 | 330 – 390 | ≥ 1,100 | ≥ 12 | 150 mm | Entry grade. Coal machinery, chutes and hoppers where a lot of welding and forming is needed. |
| NM400 | 370 – 430 | ≥ 1,200 | ≥ 10 | 150 mm | The general-purpose choice. Dump truck bodies, buckets, feeders, chutes. |
| NM450 | 420 – 480 | ≥ 1,250 | ≥ 7 | 150 mm | Mining and aggregate plant. Wide-body truck panels, crushers, heavy chutes. |
| NM500 | 470 – 540 | ≥ 1,300 | ≥ 7 | 120 mm | Severe sliding abrasion. Crusher liners, transfer points, cement and quarry plant. |
| NM550 | 520 – 580 | ≥ 1,500 | — | 80 mm | Severe abrasion in thinner sections, where wear life rather than price drives the choice. |
| NM600 | 570 – 640 | ≥ 1,600 | — | 50 mm | The hardest grade. Liners and wear parts where replacement is expensive and downtime costly. |
The harder the grade, the better the resistance to sliding abrasion — and the harder it is to cut, form, drill and weld. The hardest plate is not automatically the cheapest answer: price the whole cycle, including the fabrication step, before you specify.
International Equivalent Grades
| Standard / brand | Equivalent grade | Delivery state | Nominal hardness |
|---|---|---|---|
| GB/T 24186-2022 | NM400 / NM400D / NM400E / NM400F | Q + T | 400 HBW (370 – 430) |
| SSAB (Sweden) | Hardox® 400 | Q + T | 400 HBW |
| thyssenkrupp (Germany) | XAR® 400 | Q + T | 400 HBW |
| EMW (Germany) | QUARD® 400 | Q + T | 400 HBW |
| JFE Steel (Japan) | JFE-EH400 | Q + T | 400 HBW |
| Dillinger (Germany) | DILLIDUR® 400V | Q + T | 400 HBW |
| Sumitomo (Japan) | SUMIHARD K400 | Q + T | 400 HBW |
Cross-references are indicative only. They are based on nominal hardness and delivery condition, they are not a statement of equivalence, and grades are not interchangeable between makers — always confirm the actual data sheet for the plate you are offered, including the CEQ and the impact temperature.
Processing & Delivery Services
| Service | Capability | Effect in your workshop |
|---|---|---|
| Laser cutting & nesting | 20,000 W fibre laser, 16,000 mm × 4,000 mm table | Profiled parts nested to your drawing arrive instead of full plates |
| Plasma & oxy-fuel cutting | CNC fine plasma and oxy-fuel, with preheat control for thick and hard grades | Thick and high-hardness sections cut without edge cracking |
| Edge beveling | Double-sided edge milling up to 16,000 mm, stepless bevel angle | Weld-ready edges; no manual grinding at your site |
| Plate rolling | W11S universal rolling machine, 42 mm × 4,000 mm, crowned top roll | Chute, liner and hopper shells formed to drawing |
| Drilling & machining | Carbide tooling, rigid clamping, emulsion coolant, boring and thread milling | Bolt holes, counterbores and threads finished to drawing |
| Shot blasting & priming | Roller-conveyor line 5.2 m × 24 m, plate 5 – 120 mm, blast to Sa 2.5; weldable primer 15 – 25 µm | Clean, protected plate on arrival; no blasting shed occupancy at your site |
| Marking recovery | Inkjet restoration of heat number, grade and size | Full traceability is retained after blasting |
| Seaworthy packing | Steel strapping, timber skids and separators, container or break-bulk | Less transit damage and port handling rework |
Tell us the application and the drawing rather than just the grade, and we will quote the plate together with the cutting, forming, machining and surface preparation that gets it to your site ready to fit.
Ordering & Documentation
To quote accurately we need: grade, thickness × width × length (or a nesting drawing), quantity, hardness acceptance range if you are sampling, edge condition (sheared, flame cut or machined), surface condition (bare, blasted, or blasted and primed), destination port and required delivery date.
Every shipment is supplied with a mill test certificate traceable to heat number and plate identification. Where the contract does not specify tensile strength, elongation or impact energy, the mill guarantees Brinell hardness only — so if those properties matter for your acceptance, state them on the order.
Product Images
Wear-Resistant Steel Plates
Through the mill line
Quenched and tempered plate on the roller line before inspection and dispatch.
Wear-Resistant Steel Plates
Edge and thickness
Cut face and edge condition, with the section consistent across the plate.
Wear-Resistant Steel Plates
Yard storage
Plate stacked with timber separation so the faces stay clear of the ground.
Request NM400 Wear-Resistant Steel Plate Quotation & Mill Certificate
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