Steel A439 Type D-2 vs A48 Class 30
Steel · grade comparison
Steel A439 Type D-2 and A48 Class 30 are both steel grades. A439 Type D-2 is the stronger of the two: yield strength 250 MPa (36.3 ksi) against 150 MPa (21.8 ksi) for A48 Class 30, about 67% more; tensile strength follows at 450 MPa (65.3 ksi) vs 214 MPa (31 ksi). A439 Type D-2 is the more ductile: elongation 12% versus 0.6% for A48 Class 30, and A48 Class 30 is harder (210 HB vs 170 HB). A48 Class 30 is lighter (7.15 g/cm³ vs 7.4 g/cm³ for A439 Type D-2) and A439 Type D-2 is stiffer (120 GPa vs 100 GPa). On the shop floor, A48 Class 30 machines more easily (excellent vs fair), A439 Type D-2 welds better (fair vs poor), and A48 Class 30 sits in a lower cost tier (budget, $) than A439 Type D-2 (high, $$$$).
A439 Type D-2Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
A48 Class 30Choose it when weight is the constraint, or when the part is machined in volume.
A439 Type D-2 vs A48 Class 30: 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
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Physical
Density and transition temperatures.
Density
Liquidus Temperature
Same in both: Melting Point (Solidus) 1,150°C2,102 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 220 J/g94.6 BTU/lb
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
Castability
Brazeability / Solderability
Polishability
Formability (cold)
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 | A439 Type D-2 | A48 Class 30 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $ Budget |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
A439 Type D-2 vs A48 Class 30 — frequently asked
Is A439 Type D-2 stronger than A48 Class 30?
Yes. A439 Type D-2 has a typical yield strength of 250 MPa (36.3 ksi) against 150 MPa (21.8 ksi) for A48 Class 30 — about 67% more. Tensile strength is 450 MPa (65.3 ksi) vs 214 MPa (31 ksi).
Which is cheaper, A439 Type D-2 or A48 Class 30?
A48 Class 30 is the lower-cost material: it sits in the budget tier ($) while A439 Type D-2 is high ($$$$). 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, A439 Type D-2 or A48 Class 30?
A48 Class 30. Its machinability rates excellent (85/100) against fair (45/100) for A439 Type D-2; for welding the order is A439 Type D-2 first (fair, 50/100) then A48 Class 30 (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A439 Type D-2 and A48 Class 30 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.