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Steel 20G vs P355GH

Steel · grade comparison

Steel 20G and P355GH are both steel grades. P355GH is the stronger of the two: yield strength 385 MPa (55.8 ksi) against 275 MPa (39.9 ksi) for 20G, about 40% more; tensile strength follows at 550 MPa (79.8 ksi) vs 470 MPa (68.2 ksi). In exchange, 20G is the more ductile: elongation 28% versus 24% for P355GH, and P355GH is harder (165 HB vs 135 HB). 20G runs hotter in service (450°C vs 380°C continuous) and 20G conducts electricity better (11 % IACS vs 8.2 % IACS). On the shop floor, 20G sits in a lower cost tier (budget, $) than P355GH (standard, $$).

20GChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

P355GHChoose it when strength drives the design.

20G vs P355GH: properties

20GP355GH

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

470 MPa68.2 ksi
550 MPa79.8 ksi

Yield Strength (0.2% offset)

275 MPa39.9 ksi
385 MPa55.8 ksi

Elongation at Break

28%
24%

Reduction in Area

58%
50%

Compressive Strength

275 MPa39.9 ksi
385 MPa55.8 ksi

Shear Strength

330 MPa47.9 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

210 MPa30.5 ksi
245 MPa35.5 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

135 HB
165 HB

Hardness, Rockwell B

74 HRB
85 HRB

Hardness, Vickers

142 HV
173 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,490°C2,714 °F
1,460°C2,660 °F

Liquidus Temperature

1,520°C2,768 °F
1,510°C2,750 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.1 µm/m·K6.7 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

450°C842 °F
380°C716 °F

Min Service Temperature

-20°C-4 °F
-10°C14 °F

Same in both: Thermal Conductivity 48 W/m·K27.7 BTU/hr·ft·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

11 % 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).

Galvanic Potential (seawater, vs SCE)

-0.65 V
-0.62 V

Corrosion Resistance

10 / 100
12 / 100

Manufacturability

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

Machinability

65 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
62%

Weldability

92 / 100
85 / 100

Formability (cold)

82 / 100
64 / 100

Brazeability / Solderability

65 / 100
50 / 100

Same in both: Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

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

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

60 kN·m/kg
70 kN·m/kg

Modulus of Resilience

180 kJ/m³
353 kJ/m³

Thermal Diffusivity

13 mm²/s
13.3 mm²/s

Thermal Shock Resistance Index

9
10

Same in both: Specific Stiffness (E / density) 26.8 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleP355GH20G

Manufacturing and finishing

Capability20GP355GH
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.

20G vs P355GH — frequently asked

Is P355GH stronger than 20G?

Yes. P355GH has a typical yield strength of 385 MPa (55.8 ksi) against 275 MPa (39.9 ksi) for 20G — about 40% more. Tensile strength is 550 MPa (79.8 ksi) vs 470 MPa (68.2 ksi).

Which is cheaper, 20G or P355GH?

20G 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 is easier to machine, 20G or P355GH?

20G, by a small margin. Both rate good for machinability — 65/100 against 58/100 for P355GH; for welding the order is 20G first (excellent, 92/100) then P355GH (excellent, 85/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20G 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.