FabDigitFabDigit

Steel 34MnB5 vs P420M

Steel · grade comparison

Steel 34MnB5 and P420M are both steel grades. P420M is the stronger of the two: yield strength 445 MPa (64.5 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 6% more. P420M is the more ductile: elongation 24% versus 14% for 34MnB5, and 34MnB5 is harder (185 HB vs 175 HB). P420M conducts electricity better (10 % IACS vs 8 % IACS). On the shop floor, P420M welds better (excellent vs good) and P420M sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

P420MChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

34MnB5 vs P420M: properties

34MnB5P420M

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
570 MPa82.7 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
445 MPa64.5 ksi

Elongation at Break

14%
24%

Reduction in Area

45%
55%

Shear Strength

400 MPa58 ksi
350 MPa50.8 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
265 MPa38.4 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
130 MPa·√m118 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
180 J133 ft·lbf

Hardness, Brinell

185 HB
175 HB

Hardness, Rockwell B

89 HRB
88 HRB

Hardness, Vickers

195 HV
185 HV

Compressive Strength

—
445 MPa64.5 ksi

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,460°C2,660 °F

Liquidus Temperature

1,495°C2,723 °F
1,510°C2,750 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Expansion (CTE, 20–100 °C)

12.5 µm/m·K6.9 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

Min Service Temperature

-40°C-40 °F
-20°C-4 °F

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
10 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
1.7×10⁻⁷ Ω·m6.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.62 V

Corrosion Resistance

11 / 100
12 / 100

Manufacturability

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

Machinability

55 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Weldability

55 / 100
85 / 100

Formability (cold)

60 / 100
62 / 100

Polishability

55 / 100
45 / 100

Same in both: Brazeability / Solderability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2 kg CO₂/kg
2.1 kg CO₂/kg

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
73 kN·m/kg

Modulus of Resilience

420 kJ/m³
471 kJ/m³

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg · Thermal Diffusivity 11.9 mm²/s · Thermal Shock Resistance Index 10

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 scale34MnB5P420M

Manufacturing and finishing

Capability34MnB5P420M
Sheet metalYes—
Default conditionCR—
Relative cost$$ Standard$ Budget
Min. machined wall——
Best machined surface——
Black OxideYes—
CerakoteYes—
Chrome PlatingYes—
E-CoatingYes—
Hot-Dip GalvanizingYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Powder CoatingYes—
Tin PlatingYes—
Zinc PlatingYes—
Zinc-Flake (Dip-Spin) CoatingYes—
Zinc-Nickel PlatingYes—

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

34MnB5 vs P420M — frequently asked

Is P420M stronger than 34MnB5?

Yes. P420M has a typical yield strength of 445 MPa (64.5 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 6% more. Tensile strength is 570 MPa (82.7 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 34MnB5 or P420M?

P420M is the lower-cost material: it sits in the budget tier ($) while 34MnB5 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 welds better, 34MnB5 or P420M?

P420M. Its weldability rates excellent (85/100) against good (55/100) for 34MnB5.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34MnB5 and P420M 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.