Steel A842 Grade 300 vs A842 Grade 400
Steel · grade comparison
Steel A842 Grade 300 and A842 Grade 400 are both steel grades. A842 Grade 400 is the stronger of the two: yield strength 350 MPa (50.8 ksi) against 230 MPa (33.4 ksi) for A842 Grade 300, about 52% more; tensile strength follows at 430 MPa (62.4 ksi) vs 330 MPa (47.9 ksi). In exchange, A842 Grade 300 is the more ductile: elongation 2.5% versus 2% for A842 Grade 400, and A842 Grade 400 is harder (220 HB vs 170 HB). A842 Grade 300 runs hotter in service (400°C vs 350°C continuous).
A842 Grade 300Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
A842 Grade 400Choose it when strength drives the design.
A842 Grade 300 vs A842 Grade 400: 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.
Bulk Modulus
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
Reduction in Area
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 145 GPa21 Msi · Shear Modulus 57 GPa8.3 Msi · Poisson's Ratio 0.26
Physical
Density and transition temperatures.
Liquidus Temperature
Same in both: Density 7.1 g/cm³0.26 lb/in³ · Melting Point (Solidus) 1,150°C2,102 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Max Service Temperature (continuous)
Same in both: Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 220 J/g94.6 BTU/lb · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Electrical Conductivity
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
Castability
Polishability
Same in both: Formability (cold) 5 / 100 · Brazeability / Solderability 40 / 100
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)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 20.4 MN·m/kg
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 | A842 Grade 300 | A842 Grade 400 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ 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.
A842 Grade 300 vs A842 Grade 400 — frequently asked
Is A842 Grade 400 stronger than A842 Grade 300?
Yes. A842 Grade 400 has a typical yield strength of 350 MPa (50.8 ksi) against 230 MPa (33.4 ksi) for A842 Grade 300 — about 52% more. Tensile strength is 430 MPa (62.4 ksi) vs 330 MPa (47.9 ksi).
Which is cheaper, A842 Grade 300 or A842 Grade 400?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, A842 Grade 300 or A842 Grade 400?
A842 Grade 300, by a small margin. Both rate fair for machinability — 40/100 against 35/100 for A842 Grade 400; for welding the order is A842 Grade 400 first (poor, 30/100) then A842 Grade 300 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A842 Grade 300 and A842 Grade 400 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.