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Steel A514 Grade B vs NM400

Steel · grade comparison

Steel A514 Grade B and NM400 are both steel grades. NM400 is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 760 MPa (110 ksi) for A514 Grade B, about 38% more; tensile strength follows at 1,250 MPa (181 ksi) vs 820 MPa (119 ksi). In exchange, A514 Grade B is the more ductile: elongation 19% versus 12% for NM400, and NM400 is harder (400 HB vs 255 HB). A514 Grade B runs hotter in service (400°C vs 250°C continuous). On the shop floor, A514 Grade B machines more easily (fair vs poor) and A514 Grade B sits in a lower cost tier (budget, $) than NM400 (standard, $$).

A514 Grade BChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

NM400Choose it when strength drives the design.

A514 Grade B vs NM400: properties

A514 Grade BNM400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
210 GPa30.5 Msi

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi

Tensile Strength (Ultimate)

820 MPa119 ksi
1,250 MPa181 ksi

Yield Strength (0.2% offset)

760 MPa110 ksi
1,050 MPa152 ksi

Elongation at Break

19%
12%

Reduction in Area

50%
40%

Compressive Strength

760 MPa110 ksi
1,100 MPa160 ksi

Shear Strength

490 MPa71.1 ksi
750 MPa109 ksi

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
550 MPa79.8 ksi

Fracture Toughness (K_IC)

140 MPa·√m127 ksi·√in
70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

255 HB
400 HB

Hardness, Rockwell C

25 HRC
42 HRC

Hardness, Vickers

270 HV
420 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
250°C482 °F

Min Service Temperature

-50°C-58 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

15 / 100
12 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V

Manufacturability

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

Machinability

35 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
25%

Weldability

60 / 100
55 / 100

Formability (cold)

35 / 100
30 / 100

Brazeability / Solderability

40 / 100
30 / 100

Same in both: Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Water

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

Typical Recycled Content

30%
20%

Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

104 kN·m/kg
159 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

1,409 kJ/m³
2,625 kJ/m³

Thermal Diffusivity

11.4 mm²/s
10.8 mm²/s

Thermal Shock Resistance Index

14
20

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 scaleNM400A514 Grade B

Manufacturing and finishing

CapabilityA514 Grade BNM400
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.

A514 Grade B vs NM400 — frequently asked

Is NM400 stronger than A514 Grade B?

Yes. NM400 has a typical yield strength of 1,050 MPa (152 ksi) against 760 MPa (110 ksi) for A514 Grade B — about 38% more. Tensile strength is 1,250 MPa (181 ksi) vs 820 MPa (119 ksi).

Which is cheaper, A514 Grade B or NM400?

A514 Grade B 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, A514 Grade B or NM400?

A514 Grade B. Its machinability rates fair (35/100) against poor (25/100) for NM400; for welding the order is A514 Grade B first (good, 60/100) then NM400 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A514 Grade B 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.