Steel 4130 vs P20
Steel · grade comparison
Steel 4130 and P20 are both steel grades. Both yield at about 440 MPa — strength does not separate them. P20 is harder — 315 HV against 228 HV for 4130 — which matters for wear surfaces and threads. P20 runs hotter in service (450°C vs 400°C continuous) and 4130 conducts heat better (42.7 W/m·K vs 32 W/m·K). On the shop floor, P20 machines more easily (65 vs 55 out of 100), 4130 welds better (good vs fair), and 4130 forms better (fair vs poor).
4130Choose it when it will be welded, or when cost is the deciding factor.
P20Choose it when surface hardness matters, or when the part sees heat.
4130 vs P20: 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.
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Hardness, Rockwell C
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 · Tensile Strength (Ultimate) 700 MPa102 ksi · Yield Strength (0.2% offset) 440 MPa63.8 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
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Modulus of Resilience 472 kJ/m³
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 | 4130 | P20 |
|---|---|---|
| Sheet metal | Yes | — |
| Default condition | HR | Annealed |
| Relative cost | $$ Standard | $$$$$ Specialty |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.
4130 vs P20 — frequently asked
What is the difference between 4130 and P20?
Steel 4130 and P20 are both steel grades. Both yield at about 440 MPa — strength does not separate them. P20 is harder — 315 HV against 228 HV for 4130 — which matters for wear surfaces and threads.
Which is cheaper, 4130 or P20?
4130 is the lower-cost material: it sits in the standard tier ($$) while P20 is specialty ($$$$$). 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, 4130 or P20?
P20, by a small margin. Both rate good for machinability — 65/100 against 55/100 for 4130; for welding the order is 4130 first (good, 65/100) then P20 (fair, 50/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4130 and P20 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.