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Steel NM360 vs NM400

Steel · grade comparison

Steel NM360 and NM400 are both steel grades. Both yield at about 1,000 MPa — strength does not separate them. NM400 is harder — 400 HB against 360 HB for NM360 — which matters for wear surfaces and threads. NM400 conducts electricity better (8 % IACS vs 7 % IACS). On the shop floor, NM360 welds better (65 vs 55 out of 100), NM360 forms better (fair vs poor), and NM360 sits in a lower cost tier (budget, $) than NM400 (standard, $$).

NM360Choose it when it will be welded, or when cost is the deciding factor.

NM400Choose it when surface hardness matters.

NM360 vs NM400: properties

NM360NM400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi

Tensile Strength (Ultimate)

1,200 MPa174 ksi
1,250 MPa181 ksi

Yield Strength (0.2% offset)

1,000 MPa145 ksi
1,050 MPa152 ksi

Elongation at Break

11%
12%

Reduction in Area

45%
40%

Compressive Strength

1,050 MPa152 ksi
1,100 MPa160 ksi

Shear Strength

720 MPa104 ksi
750 MPa109 ksi

Fatigue Strength (Endurance Limit)

520 MPa75.4 ksi
550 MPa79.8 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
70 MPa·√m63.7 ksi·√in

Hardness, Brinell

360 HB
400 HB

Hardness, Rockwell C

38 HRC
42 HRC

Hardness, Vickers

380 HV
420 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29 · Charpy V-Notch Impact (RT) 45 J33.2 ft·lbf

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,425°C2,597 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,500°C2,732 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Expansion (CTE, 20–100 °C)

12.2 µm/m·K6.8 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Same in both: Thermal Conductivity 40 W/m·K23.1 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 250°C482 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7 % IACS
8 % IACS

Electrical Resistivity

2.4×10⁻⁷ Ω·m9.45 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.62 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

30 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
25%

Weldability

65 / 100
55 / 100

Formability (cold)

40 / 100
30 / 100

Brazeability / Solderability

25 / 100
30 / 100

Polishability

50 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

25%
20%

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

153 kN·m/kg
159 kN·m/kg

Modulus of Resilience

2,381 kJ/m³
2,625 kJ/m³

Thermal Shock Resistance Index

19
20

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg · Thermal Diffusivity 10.8 mm²/s

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleNM400NM360

Manufacturing and finishing

CapabilityNM360NM400
CNC machining—Yes
Sheet metal—Yes
Default condition—Q&T
Relative cost$ Budget$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

NM360 vs NM400 — frequently asked

What is the difference between NM360 and NM400?

Steel NM360 and NM400 are both steel grades. Both yield at about 1,000 MPa — strength does not separate them. NM400 is harder — 400 HB against 360 HB for NM360 — which matters for wear surfaces and threads.

Which is cheaper, NM360 or NM400?

NM360 is the lower-cost material: it sits in the budget tier ($) while NM400 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, NM360 or NM400?

NM360, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for NM400; for welding the order is NM360 first (good, 65/100) then NM400 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in NM360 and NM400 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.