Steel P3 vs P4
Steel · grade comparison
Steel P3 and P4 are both steel grades. P3 is the stronger of the two: yield strength 340 MPa (49.3 ksi) against 300 MPa (43.5 ksi) for P4, about 13% more; tensile strength follows at 540 MPa (78.3 ksi) vs 500 MPa (72.5 ksi). P3 is the more ductile: elongation 28% versus 25% for P4, and P3 is harder (160 HB vs 122 HB). P3 conducts heat better (40 W/m·K vs 26 W/m·K). On the shop floor, P3 welds better (good vs fair) and P3 sits in a lower cost tier (standard, $$) than P4 (premium, $$$).
P3Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
P3 vs P4: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Fatigue Strength (Endurance Limit) 250 MPa36.3 ksi
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Min Service Temperature
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 30%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | P3 | P4 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$$ Premium |
| 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.
P3 vs P4 — frequently asked
Is P3 stronger than P4?
Yes. P3 has a typical yield strength of 340 MPa (49.3 ksi) against 300 MPa (43.5 ksi) for P4 — about 13% more. Tensile strength is 540 MPa (78.3 ksi) vs 500 MPa (72.5 ksi).
Which is cheaper, P3 or P4?
P3 is the lower-cost material: it sits in the standard tier ($$) while P4 is premium ($$$). 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, P3 or P4?
P3. Its weldability rates good (65/100) against fair (45/100) for P4.
Ready to make it?
Upload a CAD file and FabDigit prices the part in P3 and P4 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.