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Steel A285 vs P355GH

Steel · grade comparison

Steel A285 and P355GH are both steel grades, both pressure vessel steel. P355GH is the stronger of the two: yield strength 385 MPa (55.8 ksi) against 250 MPa (36.3 ksi) for A285, about 54% more; tensile strength follows at 550 MPa (79.8 ksi) vs 450 MPa (65.3 ksi). In exchange, A285 is the more ductile: elongation 30% versus 24% for P355GH, and P355GH is harder (165 HB vs 130 HB). A285 runs hotter in service (425°C vs 380°C continuous) and A285 conducts electricity better (10.8 % IACS vs 8.2 % IACS). On the shop floor, A285 machines more easily (68 vs 58 out of 100).

A285Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

P355GHChoose it when strength drives the design.

A285 vs P355GH: properties

A285P355GH

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
210 GPa30.5 Msi

Shear Modulus

79 GPa11.5 Msi
81 GPa11.7 Msi

Tensile Strength (Ultimate)

450 MPa65.3 ksi
550 MPa79.8 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
385 MPa55.8 ksi

Elongation at Break

30%
24%

Reduction in Area

55%
50%

Compressive Strength

250 MPa36.3 ksi
385 MPa55.8 ksi

Shear Strength

290 MPa42.1 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
245 MPa35.5 ksi

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

130 HB
165 HB

Hardness, Rockwell B

72 HRB
85 HRB

Hardness, Vickers

—
173 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Fracture Toughness (K_IC) 100 MPa·√m91 ksi·√in

Physical

Density and transition temperatures.

Liquidus Temperature

1,515°C2,759 °F
1,510°C2,750 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,460°C2,660 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

51 W/m·K29.5 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F

Specific Heat Capacity

470 J/kg·K0.11 BTU/lb·°F
461 J/kg·K0.11 BTU/lb·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
260 J/g112 BTU/lb

Max Service Temperature (continuous)

425°C797 °F
380°C716 °F

Min Service Temperature

-29°C-20 °F
-10°C14 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.8 % IACS
8.2 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
2.1×10⁻⁷ Ω·m8.27 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 100
12 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

68 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
62%

Weldability

92 / 100
85 / 100

Formability (cold)

82 / 100
64 / 100

Brazeability / Solderability

60 / 100
50 / 100

Polishability

40 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

30 L/kg3.6 gal/lb
40 L/kg4.8 gal/lb

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

57 kN·m/kg
70 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

156 kJ/m³
353 kJ/m³

Thermal Diffusivity

13.8 mm²/s
13.3 mm²/s

Same in both: Thermal Shock Resistance Index 10

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleA285P355GH

Manufacturing and finishing

CapabilityA285P355GH
Default conditionHRHR
Relative cost$$ Standard$$ Standard
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining and Sheet metal. 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.

A285 vs P355GH — frequently asked

Is P355GH stronger than A285?

Yes. P355GH has a typical yield strength of 385 MPa (55.8 ksi) against 250 MPa (36.3 ksi) for A285 — about 54% more. Tensile strength is 550 MPa (79.8 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, A285 or P355GH?

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, A285 or P355GH?

A285, by a small margin. Both rate good for machinability — 68/100 against 58/100 for P355GH; for welding the order is A285 first (excellent, 92/100) then P355GH (excellent, 85/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A285 and P355GH 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.