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Steel A372 Grade A vs P355GH

Steel · grade comparison

Steel A372 Grade A and P355GH are both steel grades. P355GH is the stronger of the two: yield strength 385 MPa (55.8 ksi) against 300 MPa (43.5 ksi) for A372 Grade A, about 28% more. P355GH is harder — 165 HB against 155 HB for A372 Grade A — which matters for wear surfaces and threads. A372 Grade A runs hotter in service (425°C vs 380°C continuous) and A372 Grade A conducts electricity better (10 % IACS vs 8.2 % IACS). On the shop floor, P355GH welds better (excellent vs very good) and A372 Grade A sits in a lower cost tier (budget, $) than P355GH (standard, $$).

A372 Grade AChoose it when the part sees heat, or when cost is the deciding factor.

P355GHChoose it when strength drives the design, or when surface hardness matters.

A372 Grade A vs P355GH: properties

A372 Grade AP355GH

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)

530 MPa76.9 ksi
550 MPa79.8 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
385 MPa55.8 ksi

Elongation at Break

26%
24%

Compressive Strength

300 MPa43.5 ksi
385 MPa55.8 ksi

Shear Strength

330 MPa47.9 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
245 MPa35.5 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

155 HB
165 HB

Hardness, Rockwell B

82 HRB
85 HRB

Hardness, Vickers

162 HV
173 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 50%

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,460°C2,660 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 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 % IACS
8.2 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 µΩ·in
2.1×10⁻⁷ Ω·m8.27 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.62 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

62 / 100
58 / 100

Weldability

75 / 100
85 / 100

Formability (cold)

60 / 100
64 / 100

Castability

50 / 100
—

Brazeability / Solderability

65 / 100
50 / 100

Polishability

55 / 100
45 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 62%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

26 MJ/kg11,178 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
1.9 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
40 L/kg4.8 gal/lb

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

68 kN·m/kg
70 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

225 kJ/m³
353 kJ/m³

Thermal Diffusivity

13.6 mm²/s
13.3 mm²/s

Thermal Shock Resistance Index

11
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 scaleP355GHA372 Grade A

Manufacturing and finishing

CapabilityA372 Grade AP355GH
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

A372 Grade A vs P355GH — frequently asked

Is P355GH stronger than A372 Grade A?

Yes. P355GH has a typical yield strength of 385 MPa (55.8 ksi) against 300 MPa (43.5 ksi) for A372 Grade A — about 28% more. Tensile strength is 550 MPa (79.8 ksi) vs 530 MPa (76.9 ksi).

Which is cheaper, A372 Grade A or P355GH?

A372 Grade A is the lower-cost material: it sits in the budget tier ($) while P355GH is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, A372 Grade A or P355GH?

P355GH. Its weldability rates excellent (85/100) against very good (75/100) for A372 Grade A.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A372 Grade A 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.