Wear-Resistant Steel Plates
Through the mill line
Quenched and tempered plate on the roller line before inspection and dispatch.
Wear-Resistant Steel Plates
NM450 Wear-Resistant Steel Plate
Product Overview
NM450 is produced to GB/T 24186-2022 and supplied quenched and tempered at 420 – 480 HBW. It is the grade buyers move to when NM400 has proved correct in principle but too short-lived in practice: the step up in hardness is real, while the grade stays formable enough to be rolled into body panels and chute shells.
The forming capability is the reason NM450 is specified for mining truck body work. The grade meets a 4t → 180° cold bend requirement — it can be bent through 180 degrees on a radius of four plate thicknesses without cracking, which is what a truck body panel or a curved chute liner actually demands. Combined with a low carbon equivalent, that makes it the most common choice for the wide-body truck bodies used in large open-pit operations.
Expect the fabrication discipline to step up with the hardness. Bending force is higher and springback is more severe than on NM400, flame cutting needs a preheat below 40 mm, and edge preparation before forming becomes mandatory rather than good practice.
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. Where the part is a formed panel, we can deliver the formed panel rather than a flat plate your workshop then has to find press capacity for.
Mechanical Properties & Hardness
| Grade | Delivery | Thickness | Tensile strength Rm | Elongation A50 | Impact energy | Hardness |
|---|---|---|---|---|---|---|
| NM450E | Q + T | 6 – 150 mm | ≥ 1,250 MPa | ≥ 7 % | ≥ 24 J | 420 – 480 HBW |
Figures are the mill’s guaranteed values for NM450E/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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| NM450 | ≤ 0.35 | ≤ 0.7 | ≤ 1.7 | ≤ 0.025 | ≤ 0.010 | ≤ 1.4 | ≤ 0.8 | ≤ 0.55 | ≤ 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 |
|---|---|---|---|
| NM450 | 6 – 12 mm | 1,500 – 3,000 mm | 3,000 – 15,000 mm |
| NM450 | > 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 body panels — The grade meets a 4t → 180° cold bend requirement and is supplied in widths up to 4,000 mm, so a panel can be formed from a single plate without a longitudinal weld.
- Mining and aggregate plant — Crusher bodies, feed chutes and hopper liners in hard-rock duty.
- Heavy-duty transfer chutes — Liners at conveyor transfer points, where the material stream is fast and abrasive.
- Loader buckets and dozer blades — Cutting edges and wear strips on high-hour machines.
- Equipment with expensive downtime — Where the operating cost of stopping the plant outweighs the higher material price.
Choose NM450 when the abrasion is severe but the part still has to be cold formed — truck body panels, curved chute liners and formed hopper sections.
Step up to NM500 for flat liners in extreme sliding abrasion; stay on NM400 if the part is complex to fabricate and the extra hardness is not paying for itself.
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 | 960 / 75 rpm / mm·min−1 |
| 20 mm | Solid carbide drill | 480 / 38 rpm / mm·min−1 |
| 20 mm | Replaceable carbide drill | 400 / 30 rpm / mm·min−1 |
Recommended drilling parameters for NM450, 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 | NM450 / NM450D / NM450E / NM450F | Q + T | 450 HBW (420 – 480) |
| SSAB (Sweden) | Hardox® 450 | Q + T | 450 HBW |
| thyssenkrupp (Germany) | XAR® 450 | Q + T | 450 HBW |
| EMW (Germany) | QUARD® 450 | Q + T | 450 HBW |
| JFE Steel (Japan) | JFE-EH450 | Q + T | 450 HBW |
| Dillinger (Germany) | DILLIDUR® 450V | Q + T | 450 HBW |
| Sumitomo (Japan) | SUMIHARD K450 | Q + T | 450 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
Yard storage
Plate stacked with timber separation so the faces stay clear of the ground.
Wear-Resistant Steel Plates
Layered bundle
Layered plates showing flatness and thickness consistency in the bundle.
Wear-Resistant Steel Plates
Edge and thickness
Cut face and edge condition, with the section consistent across the plate.
Request NM450 Wear-Resistant Steel Plate Quotation & Mill Certificate
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