NM600 is a quenched-and-tempered, high-hardness abrasion-resistant steel plate specified in Chinese GB/T standards and engineered for the most demanding wear environments (mining, crushers, buckets, liners). Typical surface hardness targets center around ~600 HBW (nominal) with measured Brinell ranges commonly ~570–640 HBW, and mechanical/toughness properties engineered to combine very high hardness with acceptable weldability. NM600 is broadly equivalent in performance class to commercial grades such as Hardox® 600 (SSAB) and JFE EH600 / EVERHARD-600, and when sourced from reputable mills it meets GB/T 24186 family requirements for heavy equipment wear components.

What is NM600 steel plate?

NM600 is a wear-resistant structural plate produced by quenching and tempering or TMCP routes. The “NM” prefix in Chinese grade nomenclature comes from the pinyin “NaiMo” (耐磨) meaning “wear-resistant”; the numeric suffix indicates the nominal Brinell hardness class (600 HBW nominal). NM600 is designed to deliver long life in abrasive/impacting environments while remaining usable in welded fabrications and heavy assemblies. It is a premium product in the NM series (NM300, NM360, NM400 → NM600), intended where NM500 or NM550 no longer provide adequate service life.

Governing standards & test methods

• Chinese standard: GB/T 24186 (High strength abrasion-resistant steel plates for construction machine) defines grades, chemistry, hardening, thickness limits and test methods for NM series plates and is the most commonly referenced standard for NM600 production and acceptance in the Chinese supply chain.

• Hardness testing: Brinell hardness measurement methods follow ISO 6506 / EN ISO 6506-1 (or equivalent national adoptions) for HBW testing; reporting typically uses HBW with ball size/load indicated by the testing report. Use standardized test depth (0.5–2 mm below the surface) and report average values per standard.

Chemical composition (typical / normative values)

NOTE: composition limits vary by supplier and by the exact sub-grade or TMCP route. The table below is a representative consolidation from GB/T family listings and commercial mill data sheets. Always request mill certificates (MTC, heat-by-heat).

(Source consolidation from GB/T listings and supplier product pages — use as a procurement starting point.)

Mechanical & physical properties (typical / guaranteed)

The following table groups the usual performance parameters mills publish for NM600; final acceptance depends on thickness, heat treatment and test location.

Representative test and datasheet values for NM600 (Q+T, 6–50 mm ranges) are consistent with other high-hardness wear plates and are published by commercial suppliers.

NM600 steel plate specifications (dimensions & tolerances)

Below is a general specification grid frequently seen in seller datasheets. Exact tolerance and flatness data should be requested from the mill.

What is equivalent to NM600 steel?

NM600 occupies the same functional class as other global high-hardness abrasion steels. Common equivalents (performance class) seen in supplier literature:

• Hardox® 600 (SSAB) — nominal 600 HBW; widely regarded as a premium, tightly controlled product family.

• EH600 / EVERHARD-600 (JFE) — Japanese product in the 600 HBW class.

• AR600 / AR600 class steels — a North American-style designation used by mills and distributors for similar hardness class.

• Chinese NM600 — made to GB/T 24186 series; when properly produced it can match the key performance of the above brands for many wear cases.

Important caveat: Brand product data (e.g., Hardox®) often include tighter guaranteed full-section toughness and homogeneity; buyers should compare datasheets and ask for specific mechanical testing rather than relying on nomenclature alone.

NM600 sizes and weight

Steel weight (kg/m²) = Density (7.85 g/cm³) × thickness (mm) / 1000 ≈ 7.85 × thickness (mm) / 1000 × 1000 → simpler: 7.85 × thickness (mm) then divide by 1000 → kg per m² = 7.85 × thickness (mm) / 1000 × 1000 — simplified formula below.

Quick reference (approx.):

(Weight formula used: 7.85 × thickness(mm) / 1000 × 1000 simplified → result shown above rounded to 1 decimal.)

Example: A 2000 × 4000 mm plate at 12 mm → area = 8 m² → weight ≈ 8 × 94.2 = 753.6 kg.

Typical applications & performance trade-offs

NM600 is selected where high abrasion resistance outweighs the extra material cost and where the design can accommodate harder, less ductile steel. Typical components:

• Mining shovel and loader bucket liners, crusher liners, chutes, hoppers.

• Earthmoving blades, wear plates in aggregate and cement plants.

• Truck bodies and dump liners where thin, light panels with long wear life are required.

Trade-offs & selection notes:

• Harder grades (NM600) give longer wear life but are more demanding to weld and form. For heavy impact + abrasion combinations, consider sacrifice in thickness or use composite/hybrid materials (hardened overlay + baseplate).

• In cold service or very high-impact use, check supplier toughness guarantees; sometimes NM550 or NM500 with thick section toughness performs better overall if impact dominates.

Fabrication, welding & heat treatment

• Cutting: plasma, waterjet, or laser for thinner sections; thermal cutting for thicker plates—expect a harder heat-affected zone (HAZ). Pre- and post-fabrication controls required.

• Welding: use low hydrogen electrodes and controlled preheat (preheat commonly recommended 150–250 °C depending on thickness and CE). For thicker plates or high carbon equivalent heats, interpass temperature control and tempering post-heat may be necessary to avoid HAZ brittleness.

• Bending/forming: limited cold-forming; small radius bends may be possible for thin NM600 but expect cracking risk in thicker plates. Use thermal forming or design around flat replacements.

• Machining: possible but abrasive on tooling; plan tooling selection and feeds accordingly.

• Weld repair & hardfacing: acceptable as ABI practice, but note hardfacing filler selection must be compatible to avoid premature spalling.

Inspection, testing & quality control checklist

When specifying/purchasing NM600, require the following on the purchase order and Certificate of Conformance (MTC):

• Mill Test Certificate (EN 10204 / 3.1 or equivalent) with heat number traceability.

• Brinell hardness report (method ISO/EN 6506-1) showing values and measurement positions.

• Chemical composition heat analysis.

• Mechanical test results (tensile, yield, elongation) per thickness range.

• Charpy V-notch (if required for low-temperature service).

• Surface inspection and visual acceptance criteria.

• Dimensional tolerances and cut list confirmation.

Price comparison — United States, Europe, China (2025)

Important: steel prices change with scrap/slag, alloy specs, thickness, finishing and quantity. The bands below are aggregate indicative ranges from active market listings and trade/FOB quotes during 2025; use them only for budgeting and always request current mill or distributor firm quotes. Sources: Chinese FOB listings, Chinese wholesalers, and distributors' 2025 guidance.

How to interpret the bands:

• Lower numbers (China FOB low end) often represent commodity NM600 or AR600 class sheets sold in large minimum order quantities (MOQs) and with less stringent documentation.

• Higher numbers reflect branded product, certified mill documentation, small volumes, or value-added processing (cutting, shot blast, CNC) done before export. Always compare total landed cost (product + processing + freight + duties) and not just per-ton price.

Procurement & specification writing tips

1. Specify hardness test method and location (e.g., “HBW 5/750/30, measured 0.5–2 mm below surface, average 600 ±30 HBW, per ISO 6506-1”).

2. Demand MTC 3.1/3.2 and heat-traceability for every plate batch.

3. Define dimensional and flatness tolerances and any cutting/processing allowances.

4. Call out impact energy if application includes heavy impact or cold climate exposure.

5. Clarify welding recommendations and request mill’s recommended preheat/interpass temperatures or weld procedure specifications.

6. Ask for production route (Q+T vs TMCP) as it affects toughness and HAZ sensitivity.

7. Request sample coupon testing (hardness profile across thickness) for first production lot.

FAQs

1. Q: Is NM600 weldable?
   A: Yes. NM600 is weldable but requires controlled procedures (preheat, low H electrodes, controlled interpass) and attention to carbon equivalent and HAZ toughness. Do not weld without an approved WPS for the exact plate thickness/heat.

2. Q: Can I bend NM600 on a press brake?
   A: Not recommended for thick plates; thin plates may be cold-formed with tight radii risk. For thicker sections, design without forming or use thermal forming.

3. Q: What hardness should I expect on delivery?
   A: Typical target 570–640 HBW, with nominal 600 HBW; insist on Brinell readings on MTC.

4. Q: Is NM600 better than NM500?
   A: NM600 gives longer wear life in abrasive conditions but less ductility and more fabrication challenge than NM500. Choose based on abrasion vs impact balance.

5. Q: What standards apply to NM600?
   A: GB/T 24186 (China) for NM series; Brinell hardness per ISO/EN 6506. For cross-checking equivalence see SSAB and JFE product data sheets.

6. Q: Are there counterfeit or mislabeled NM600 plates?
   A: Yes, always verify MTC, hardness tests and supplier traceability; buy from reputable mills or qualified traders.

7. Q: What thickness range is commonly stocked?
   A: Commercially stocked between 6–50 mm; specialized production up to 80 mm exists.

8. Q: Does NM600 corrode faster due to higher alloying?
   A: NM600 is not corrosion resistant (it’s carbon/martensitic steel). If corrosion is a concern, plan coatings, galvanizing (limited), or use stainless overlays.

9. Q: How should I specify testing frequencies?
   A: Request per-heat hardness sampling and mechanical testing per accepted standard (one set per heat or per defined thickness batch) and reserve right for third-party inspection.

10. Q: Is NM600 used in body armor?
    A: Some AR600/600 HBW steels are used in ballistic plates, but armor applications require dedicated ballistic certification and specific plate processing — do not assume merchant NM600 is ballistic-rated.