Steel NM450
also Hardox 450
NM450 is a quenched and tempered abrasion-resistant plate to GB/T 24186 at about 450 HB (47 HRC), with 1250 MPa yield, 1450 MPa tensile and 10% elongation, equivalent to Hardox 450.
Reference datasheet — NM450 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT condition
NM450 tempers and conditions
NM450 is supplied in 4 conditions, soft to hard. QT is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Q&T heavy plate | Thick plate where hardness is guaranteed only near the surface; mid-thickness hardenability drops, so use for thick liners and crusher jaws rather than for full-section strength design. | 1,150 | 1,380 | 11 | 46 HRC | 7 % IACS |
Q&T low-temperature toughness class | Cleaner, Ni-bearing heat with certified −40 °C Charpy (≥27–34 J) for mining and cold-climate structures where the wear plate also carries impact load. | 1,230 | 1,430 | 11 | 47 HRC | — |
QTDefault Quenched and tempered | Standard stocked condition for plate 4–80 mm; best balance of 450 HB wear life, bendability and weldability. | 1,250 | 1,450 | 10 | 47 HRC | — |
Direct-quenched (untempered / low-temperature stress relieved), thin… | Thin gauges (≈3–12 mm) supplied direct-quenched: hardness at the top of the band and highest strength, but the lowest impact toughness — pick only for pure sliding-wear liners with little bending or shock. | 1,300 | 1,550 | 8 | 49 HRC | — |
What is NM450?
NM450 is a quenched and tempered abrasion-resistant plate to GB/T 24186 at about 450 HB (47 HRC), with 1250 MPa yield, 1450 MPa tensile and 10% elongation, equivalent to Hardox 450. It balances hardness and weldability (60) for mining and bulk-handling wear parts and is available as plate in QT, quenched Q, through-thickness QT-Z and higher-tempered QT-HT conditions. Machinability is very low (15), so holes are usually punched or thermally cut; bend radii are 4–5t, service is limited to 250 °C, and plating or pickling risks hydrogen embrittlement. NM360 welds and forms more easily. NM450 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). NM450 has a yield strength of 1,250 MPa (181 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 95% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
What is NM450 used for?
- mining equipment liners
- screen decks
- wear plates
Advantages
- High strength — 1,250 MPa (181 ksi), better than 95% of steel grades
Limitations
- Difficult to machine — 15/100, worse than 98% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
NM450 properties
Typical room-temperature values for NM450-QT; bars are the position among steel grades.
Physical3
NM450 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
NM450 has a yield strength of 1,250 MPa (181 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 95% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
NM450 is rated for continuous service to 250°C (482 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
NM450 conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of NM450 takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability7
NM450's machinability is poor (15/100, worse than 98% of steel grades); weldability good (60/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. NM450 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with NM450
Is NM450 easy to machine?
Treat as 47 HRC martensite: rigid setups, coated carbide or CBN, low speed and heavy-duty coolant; drilling and tapping are difficult, so prefer plasma/laser cutting plus punched or pre-machined holes and design in as-cut edges.
Can NM450 be welded?
Weldable with low-hydrogen consumables of matching or lower strength (E7018/ER70S-6 class); preheat roughly 100–175 °C depending on thickness and CEV, keep interpass below ~225 °C, control heat input to limit HAZ softening, and never post-weld heat treat above the tempering temperature.
Can NM450 be formed, bent or molded?
Cold bend transverse to rolling direction with punch radius about 4–5 × thickness and generous die clearance; heavy sections need press-brake tonnage roughly 3× that of mild steel, and hot forming above ~250 °C destroys the quenched hardness.
NM450 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cladle analysis, GB/T 24186 max | ≤ 0.26 | 0.2 |
| Si | ≤ 0.7 | 0.3 |
| Mn | ≤ 1.6 | 1.2 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.01 | 0 |
| Crhardenability | ≤ 1.2 | 0.5 |
| Niraised in low-temperature toughness class | ≤ 1 | 0.2 |
| Mo | ≤ 0.6 | 0.2 |
| Bboron-treated for deep hardening | ≤ 0.01 | 0 |
| Nbmicro-alloying, optional | ≤ 0.08 | 0.03 |
| Voptional | ≤ 0.08 | 0.02 |
| Tifixes N to protect boron | ≤ 0.05 | 0.02 |
| Altotal Al, deoxidation | ≥ 0.02 | 0.03 |
| Fe | balance |
What surface finishes work on NM450?
Supplied hot-rolled or shot-blasted; apply zinc-rich primer plus epoxy paint for outdoor storage, and avoid electroplating or acid pickling because of hydrogen-embrittlement risk at 450 HB.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel NM450 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Hardox 450
How much does NM450 cost?
NM450 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
NM450 — frequently asked
What is NM450 used for?
NM450 is typically used for mining equipment liners, screen decks and wear plates. In short: standard mining wear plate; 450 HB abrasion resistance; hardox 450 equivalent.
What is the yield strength of NM450?
NM450 has a typical yield strength of 1,250 MPa (181 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is NM450 easy to machine?
Not especially — machinability is rated poor (15/100, worse than 98% of steel grades). Treat as 47 HRC martensite: rigid setups, coated carbide or CBN, low speed and heavy-duty coolant; drilling and tapping are difficult, so prefer plasma/laser cutting plus punched or pre-machined holes and design in as-cut edges.
Can NM450 be welded?
Yes — weldability is rated good (60/100). Weldable with low-hydrogen consumables of matching or lower strength (E7018/ER70S-6 class); preheat roughly 100–175 °C depending on thickness and CEV, keep interpass below ~225 °C, control heat input to limit HAZ softening, and never post-weld heat treat above the tempering temperature.
What surface finishes work on NM450?
Supplied hot-rolled or shot-blasted; apply zinc-rich primer plus epoxy paint for outdoor storage, and avoid electroplating or acid pickling because of hydrogen-embrittlement risk at 450 HB.
Can NM450 be formed, bent or molded?
Cold bend transverse to rolling direction with punch radius about 4–5 × thickness and generous die clearance; heavy sections need press-brake tonnage roughly 3× that of mild steel, and hot forming above ~250 °C destroys the quenched hardness.
What is the maximum service temperature of NM450?
NM450 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between NM450-QT and NM450 QT-HT?
QT is the default condition — standard stocked condition for plate 4–80 mm; best balance of 450 HB wear life, bendability and weldability. QT-HT: thick plate where hardness is guaranteed only near the surface; mid-thickness hardenability drops, so use for thick liners and crusher jaws rather than for full-section strength design. Yield strength is 1,250 MPa in QT versus 1,150 MPa in QT-HT.
How much does NM450 cost?
NM450 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- GB/T 24186 (High-strength abrasion-resistant steel plate) (2022)
- Hardox 450 data sheet (comparison grade) — SSAB (2023)
- ASTM A514 / ASTM E140 hardness conversions — ASTM International (2019)
- ASM Handbook Vol. 1: Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.