When selecting wear resistant steel plates for mining, construction, or heavy equipment applications, NM450 and AR450 are two of the most frequently compared grades. Both are designed to deliver excellent abrasion resistance, but they originate from different standards and markets, which leads to differences in chemical composition, mechanical properties, supply chain flexibility, and cost.
As a professional wear resistant steel plate supplier, GNEE Steel helps global buyers clearly understand the difference between NM450 and AR450 to make the right purchasing decision.
| Feature | NM450 | AR450 |
|---|---|---|
| Origin | China | USA |
| Standard | GB/T 24186 (National Standard) | SAE J450 (Automotive Engineering Standard) |
| Naming | NM = (Nai Mo = Wear Resistant) + 450 (average hardness HBW) | AR = Abrasion Resistant + 450 (average hardness HBW) |
| Manufacturing | Quenched & tempered (Q&T) | Quenched & tempered (Q&T) |
What Is NM450 Wear Resistant Steel Plate?
NM450 is a Chinese standard wear resistant steel plate defined under GB/T 24186. The "NM" stands for Nai Mo , meaning abrasion resistance, while "450" refers to a nominal Brinell hardness of 450 HBW.
NM450 steel plate is produced through quenching and tempering (Q&T), resulting in a fine martensitic microstructure that balances high wear resistance with good toughness and weldability.
What Is AR450 Steel Plate?
AR450 (Abrasion Resistant 450) is a commonly used wear plate grade in North America and international markets, often based on ASTM practices rather than a single unified standard. AR450 also features a nominal hardness of 450 HBW, making it comparable to NM450 in wear resistance.
Chemical Composition (Maximum Limits, %)
| Element | NM450 (GB/T 24186) | AR450 (SAE J450) | Purpose of Variation |
|---|---|---|---|
| Carbon (C) | ≤0.22 | 0.38-0.43 | AR450 has ~80% higher carbon for increased strength and hardness |
| Silicon (Si) | ≤0.60 | 0.90-1.20 | AR450 has 50% higher Si for improved oxidation resistance and strength |
| Manganese (Mn) | ≤1.50 | 1.50-2.00 | AR450 has higher Mn for better hardenability |
| Chromium (Cr) | ≤0.80 | 0.50-1.00 | Similar ranges, enhances carbide formation for wear resistance |
| Sulfur (S) | ≤0.005 | ≤0.015 | NM450 has lower S for improved cleanliness and toughness |
| Phosphorus (P) | ≤0.025 | ≤0.025 | Same limit for both grades |
Mechanical Properties Comparison (Critical Differences)
| Property | NM450 | AR450 | Difference |
|---|---|---|---|
| Yield Strength | ≥930-1050 MPa | ≥1000-1100 MPa | AR450: +70-100 MPa (7-10% higher) |
| Tensile Strength | ≥1250 MPa | ≥1300-1400 MPa | AR450: +50-150 MPa (4-12% higher) |
| Elongation (A50) | ≥7% | ≥5-6% | NM450: 1-2% higher ductility |
| Impact Toughness (-20°C) | ≥21 J | ≥15-20 J | NM450: +1-6 J (5-40% better toughness) |
| Carbon Equivalent (Ceq) | ≤0.62 | ≤0.65-0.70 | AR450: Higher Ceq (affects weldability) |
Hardness Comparison
| Grade | Hardness Range (HBW) | Typical Value | Key Note |
|---|---|---|---|
| NM450 | 420-480 | 450 | Specified by GB/T 24186 for thickness ≤80mm |
| AR450 | 430-480 | 450 | SAE standard range, often with tighter control in commercial products |
Processability Comparison
| Process | NM450 | AR450 | Notes |
|---|---|---|---|
| Weldability | Better | Good (with preheat) | NM450's lower C and Ceq reduce preheat requirements (100-150°C vs 150-200°C for AR450) |
| Formability | Better | Fair | NM450's higher elongation (7% vs 5-6%) allows tighter bending radii |
| Cutting | Good | Good | Both can be cut with plasma, laser, oxy-fuel, or waterjet |
| Machinability | Better | More challenging | AR450's higher carbon content increases tool wear |
| Weld Repair | Easier | Requires more care | NM450 has lower risk of cold cracking |
Wear Resistance & Performance
Similar wear performance under identical conditions (both ~450 HBW)
AR450: Slightly better wear resistance in high-stress, low-impact applications due to higher strength and carbon content
NM450: Better wear performance retention under impact loads due to superior toughness
Application Recommendations
NM450 Ideal For:
Complex structures requiring good weldability and formability (chutes, hoppers with intricate shapes)
Applications with moderate abrasion + occasional impact (excavator buckets, loader components)
Low-temperature environments needing better impact toughness (-20°C impact ≥21 J)
Chinese equipment manufacturers following GB standards
AR450 Ideal For:
High-stress applications requiring maximum strength (dump truck bodies, heavy-duty liners)
American/European equipment adhering to SAE standards
Applications prioritizing strength over formability (simple, thick-walled wear parts)
Projects specifying SAE-certified materials
NM450 vs AR450: Which One Should You Choose?
Choose NM450 if:
You need stable quality and full mill test certificates (MTC)
Your project requires custom thickness, width, or cutting services
You want cost-effective pricing with reliable supply
Your application involves welding, bending, or forming
Choose AR450 if:
You are matching an existing North American specification
Your design is based on OEM AR plate references
In many cases, NM450 is a direct and reliable alternative to AR450, with competitive pricing and shorter delivery times.
Conclusion
Although NM450 and AR450 share similar hardness levels and applications, NM450 often stands out in terms of quality consistency, fabrication performance, and cost efficiency. For global buyers seeking a dependable AR450 equivalent wear resistant steel plate, NM450 from GNEE Steel is a proven solution.
📩 Contact GNEE Steel today to get technical support, pricing, and a customized NM450 solution for your project.
What are the properties of NM450 steel?
Mechanical Properties: Yield strength ≥1000 MPa, tensile strength 1250-1400 MPa, and elongation ≥10%. These values ensure NM450 can endure extreme conditions. Thickness and Dimensions: Available in plates from 3-80mm thick, with widths up to 3000mm and lengths up to 12000mm, customizable for specific needs.
What is AR450 steel used for?
AR450 Steel Plate is used in a wide range of industries where components face abrasive contact and impact loading. Common applications include: Loader and excavator bucket liners. Dump body and truck bed liners.
What is the difference between AR400 and AR450?
AR400 vs. AR450: With an HBW of 430-480, AR450 is slightly harder and more wear-resistant than AR400 but maintains similar It is not as easy to weld or form as AR400 but is more formable than AR500.
What is the yield strength of AR450?
around 175,000 lbs
AR450 has a yield strength of around 175,000 lbs minimum yield. That is 75% stronger than 100K steel, and 250% stronger than 50K steel. The strength of AR450 steel can improve weight savings over 50K much like 100K material because a thinner material can be used without sacrificing strength.
| Other steel plate by GNEE | ||||
| Name | Material | Specification (mm) | Tons | Remark |
| Clad steel plate | P265GH+410,S355JR+410,A516Gr70+316, A537CL1+304L,Q235B+304L,Q345B+304, A516Gr70(NACE)+410,A537CL1+904L, A537CL1+316L,A516Gr70+304L,A537CL1+304 ,A516Gr70+410,A516Gr70+904L |
2-300mm(Based plate),1-50mm(Composited plate) | / | UT, AR, TMCP.Normalized, Quenched and Tempered,Z Direction Test, Charpy V-Notch impact TestThe Third Party Test , Coated or Shot Blasting and Painting. |
| Low Alloy | Q345A, Q345B, Q345C, Q345D, Q345E, Q390, Q420, Q460C, ST52-3, S355J2+N, SS400, SA302GrC, S275NL, 35CrMo | 6 - 350 | 5788.56 | Normalizing, tempered ,controlled rolling, hot rolling , Hot rolling,1st inspection, 2nd inspection, 3rd inspection |
| Pressure Vessel Plate | A204 Grade B,A515 Grade 70,A537 Class 1,SA387 Grade 11 Class 1,P265GH,S537 Class 2,P355Q,P275N,P355N,P690Q,Q345R, | 3 - 300 | 8650 | Normalizing, tempered ,controlled rolling, hot rolling , Hot rolling,1st inspection, 2nd inspection, 3rd inspection |
| High-Strength Plate | A514 Grade F, A572 Grade 50, A588 Grade A, S355JR, S690Q, SS400, S690QL, Q345B, Q345E | 8 - 120 | 3086.352 | Quenched and tempered |
| Wear-Resistant Plate | NM360, NM400, NM450, NM500 | 6 - 150 | 3866.297 | Quenched and tempered |
| Ship Plate | ABS AH32,ABS DH32,ABS EH32,ABS FH36,ASTM A131 A, ASTM A131 EH32,ASTM A131 AH36,CCS A,CCS AH32,LR AH32, DNV A36,BV AH32 |
8 - 200 | 2853.621 | Hot rolling, normalized ,hot rolling controlled rolling, quenched and tempered + toughness and brittleness |
