Steel HPM38 vs P1
Steel · grade comparison
Steel HPM38 and P1 are both steel grades. HPM38 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 240 MPa (34.8 ksi) for P1, about 117% more; tensile strength follows at 760 MPa (110 ksi) vs 380 MPa (55.1 ksi). In exchange, P1 is the more ductile: elongation 35% versus 18% for HPM38, and HPM38 is harder (215 HB vs 120 HB). HPM38 runs hotter in service (400°C vs 350°C continuous) and P1 conducts heat better (50 W/m·K vs 20 W/m·K). On the shop floor, P1 machines more easily (good vs fair), P1 welds better (excellent vs poor), and P1 sits in a lower cost tier (standard, $$) than HPM38 (premium, $$$).
HPM38Choose 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 the part is machined in volume.
HPM38 vs P1: 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.
Shear Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
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 C
Hardness, Vickers
Hardness, Rockwell B
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
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)
Castability
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)
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 | HPM38 | P1 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$ Premium | $$ 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.
HPM38 vs P1 — frequently asked
Is HPM38 stronger than P1?
Yes. HPM38 has a typical yield strength of 520 MPa (75.4 ksi) against 240 MPa (34.8 ksi) for P1 — about 117% more. Tensile strength is 760 MPa (110 ksi) vs 380 MPa (55.1 ksi).
Which is cheaper, HPM38 or P1?
P1 is the lower-cost material: it sits in the standard tier ($$) while HPM38 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, HPM38 or P1?
P1. Its machinability rates good (60/100) against fair (45/100) for HPM38; for welding the order is P1 first (excellent, 85/100) then HPM38 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in HPM38 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.