Steel A48 Class 20 vs A48 Class 30
Steel · grade comparison
Steel A48 Class 20 and A48 Class 30 are both steel grades. A48 Class 30 is the stronger of the two: tensile strength 214 MPa (31 ksi) against 152 MPa (22 ksi) for A48 Class 20, about 41% more. A48 Class 30 is the more ductile: elongation 0.6% versus 0.5% for A48 Class 20, and A48 Class 30 is harder (210 HB vs 156 HB). A48 Class 30 is stiffer (100 GPa vs 80 GPa) and A48 Class 30 runs hotter in service (400°C vs 350°C continuous).
A48 Class 30Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
A48 Class 20 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
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Yield Strength (0.2% offset)
Charpy V-Notch Impact (RT)
Same in both: Poisson's Ratio 0.26
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)
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 220 J/g94.6 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 2.2 % IACS
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 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)
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 1.6 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
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 | A48 Class 20 | A48 Class 30 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $ Budget | $ 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.
A48 Class 20 vs A48 Class 30 — frequently asked
Is A48 Class 30 stronger than A48 Class 20?
Yes. A48 Class 30 has a typical tensile strength of 214 MPa (31 ksi) against 152 MPa (22 ksi) for A48 Class 20 — about 41% more.
Which is cheaper, A48 Class 20 or A48 Class 30?
Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, A48 Class 20 or A48 Class 30?
A48 Class 20, by a small margin. Both rate excellent for machinability — 90/100 against 85/100 for A48 Class 30; for welding the order is A48 Class 30 first (poor, 30/100) then A48 Class 20 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A48 Class 20 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.