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Steel 3Cr2Mo vs P1

Steel · grade comparison

Steel 3Cr2Mo and P1 are both steel grades. 3Cr2Mo is the stronger of the two: yield strength 830 MPa (120 ksi) against 240 MPa (34.8 ksi) for P1, about 3.5 times as much; tensile strength follows at 1,000 MPa (145 ksi) vs 380 MPa (55.1 ksi). In exchange, P1 is the more ductile: elongation 35% versus 15% for 3Cr2Mo, and 3Cr2Mo is harder (300 HB vs 120 HB). 3Cr2Mo runs hotter in service (400°C vs 350°C continuous) and P1 conducts heat better (50 W/m·K vs 32 W/m·K). On the shop floor, P1 welds better (excellent vs fair).

3Cr2MoChoose it when strength drives the design, or when the part sees heat.

P1Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

3Cr2Mo vs P1: properties

3Cr2MoP1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

1,000 MPa145 ksi
380 MPa55.1 ksi

Yield Strength (0.2% offset)

830 MPa120 ksi
240 MPa34.8 ksi

Elongation at Break

15%
35%

Reduction in Area

50%
62%

Compressive Strength

860 MPa125 ksi
250 MPa36.3 ksi

Shear Strength

620 MPa89.9 ksi
260 MPa37.7 ksi

Fatigue Strength (Endurance Limit)

450 MPa65.3 ksi
180 MPa26.1 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
120 MPa·√m109 ksi·√in

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

300 HB
120 HB

Hardness, Rockwell C

30 HRC
—

Hardness, Vickers

315 HV
125 HV

Hardness, Rockwell B

—
68 HRB

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,425°C2,597 °F

Liquidus Temperature

1,490°C2,714 °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 Conductivity

32 W/m·K18.5 BTU/hr·ft·°F
50 W/m·K28.9 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

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

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Min Service Temperature

-30°C-22 °F
-20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
11 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
1.6×10⁻⁷ Ω·m6.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.55 V
-0.61 V

Corrosion Resistance

14 / 100
10 / 100

Manufacturability

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

Machinability

55 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
65%

Weldability

40 / 100
85 / 100

Formability (cold)

15 / 100
90 / 100

Brazeability / Solderability

40 / 100
75 / 100

Polishability

70 / 100
55 / 100

Castability

—
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.4 kg CO₂/kg
1.9 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

35%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

127 kN·m/kg
48 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

1,640 kJ/m³
140 kJ/m³

Thermal Diffusivity

8.9 mm²/s
13.6 mm²/s

Thermal Shock Resistance Index

12
8

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 scaleP13Cr2Mo

Manufacturing and finishing

Capability3Cr2MoP1
Default condition——
Relative cost$$ Standard$$ Standard
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

3Cr2Mo vs P1 — frequently asked

Is 3Cr2Mo stronger than P1?

Yes. 3Cr2Mo has a typical yield strength of 830 MPa (120 ksi) against 240 MPa (34.8 ksi) for P1 — about 3.5 times as much. Tensile strength is 1,000 MPa (145 ksi) vs 380 MPa (55.1 ksi).

Which is cheaper, 3Cr2Mo or P1?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 3Cr2Mo or P1?

P1, by a small margin. Both rate good for machinability — 60/100 against 55/100 for 3Cr2Mo; for welding the order is P1 first (excellent, 85/100) then 3Cr2Mo (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 3Cr2Mo and P1 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.