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Steel P1 vs P3

Steel · grade comparison

Steel P1 and P3 are both steel grades. P3 is the stronger of the two: yield strength 340 MPa (49.3 ksi) against 240 MPa (34.8 ksi) for P1, about 42% more; tensile strength follows at 540 MPa (78.3 ksi) vs 380 MPa (55.1 ksi). In exchange, P1 is the more ductile: elongation 35% versus 28% for P3, and P3 is harder (160 HB vs 120 HB). P3 runs hotter in service (400°C vs 350°C continuous) and P1 conducts heat better (50 W/m·K vs 40 W/m·K). On the shop floor, P1 welds better (excellent vs good).

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

P3Choose it when strength drives the design, or when the part sees heat.

P1 vs P3: properties

P1P3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

380 MPa55.1 ksi
540 MPa78.3 ksi

Yield Strength (0.2% offset)

240 MPa34.8 ksi
340 MPa49.3 ksi

Elongation at Break

35%
28%

Reduction in Area

62%
60%

Compressive Strength

250 MPa36.3 ksi
345 MPa50 ksi

Shear Strength

260 MPa37.7 ksi
350 MPa50.8 ksi

Fatigue Strength (Endurance Limit)

180 MPa26.1 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

120 J88.5 ft·lbf
110 J81.1 ft·lbf

Hardness, Brinell

120 HB
160 HB

Hardness, Rockwell B

68 HRB
84 HRB

Hardness, Vickers

125 HV
—

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Liquidus Temperature

1,510°C2,750 °F
1,500°C2,732 °F

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

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12 µm/m·K6.7 µin/in·°F
11.9 µm/m·K6.6 µin/in·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-20°C-4 °F
-40°C-40 °F

Same in both: Latent Heat of Fusion 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

11 % IACS
8.5 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
2×10⁻⁷ Ω·m7.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.6 V

Corrosion Resistance

10 / 100
12 / 100

Manufacturability

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

Machinability

60 / 100
62 / 100

Weldability

85 / 100
65 / 100

Formability (cold)

90 / 100
70 / 100

Castability

40 / 100
35 / 100

Brazeability / Solderability

75 / 100
55 / 100

Polishability

55 / 100
50 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 65%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
50 L/kg6 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

48 kN·m/kg
69 kN·m/kg

Modulus of Resilience

140 kJ/m³
282 kJ/m³

Thermal Diffusivity

13.6 mm²/s
11.1 mm²/s

Thermal Shock Resistance Index

8
9

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg

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 scaleP1P3

Manufacturing and finishing

CapabilityP1P3
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.

P1 vs P3 — frequently asked

Is P3 stronger than P1?

Yes. P3 has a typical yield strength of 340 MPa (49.3 ksi) against 240 MPa (34.8 ksi) for P1 — about 42% more. Tensile strength is 540 MPa (78.3 ksi) vs 380 MPa (55.1 ksi).

Which is cheaper, P1 or P3?

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 welds better, P1 or P3?

P1. Its weldability rates excellent (85/100) against good (65/100) for P3.

Ready to make it?

Upload a CAD file and FabDigit prices the part in P1 and P3 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.