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Steel 35# vs A356 Grade 8

Steel · grade comparison

Steel 35# and A356 Grade 8 are both steel grades. A356 Grade 8 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 330 MPa (47.9 ksi) for 35#, about 36% more; tensile strength follows at 655 MPa (95 ksi) vs 560 MPa (81.2 ksi). A356 Grade 8 is harder — 200 HB against 160 HB for 35# — which matters for wear surfaces and threads. A356 Grade 8 runs hotter in service (620°C vs 400°C continuous) and 35# conducts heat better (49 W/m·K vs 35 W/m·K). On the shop floor, 35# machines more easily (good vs fair), 35# welds better (good vs fair), and 35# forms better (fair vs not recommended).

35#Choose it when the part is machined in volume, or when it will be welded.

A356 Grade 8Choose it when strength drives the design, or when surface hardness matters.

35# vs A356 Grade 8: properties

35#A356 Grade 8

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

560 MPa81.2 ksi
655 MPa95 ksi

Yield Strength (0.2% offset)

330 MPa47.9 ksi
450 MPa65.3 ksi

Elongation at Break

22%
20%

Reduction in Area

50%
45%

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
285 MPa41.3 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
95 MPa·√m86.5 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

160 HB
200 HB

Hardness, Rockwell B

83 HRB
93 HRB

Hardness, Vickers

168 HV
210 HV

Compressive Strength

—
450 MPa65.3 ksi

Hardness, Rockwell C

—
15 HRC

Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Shear Strength 400 MPa58 ksi

Physical

Density and transition temperatures.

Density

7.85 g/cm³0.28 lb/in³
7.78 g/cm³0.28 lb/in³

Same in both: Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F

Thermal

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

Thermal Conductivity

49 W/m·K28.3 BTU/hr·ft·°F
35 W/m·K20.2 BTU/hr·ft·°F

Specific Heat Capacity

477 J/kg·K0.11 BTU/lb·°F
460 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.6 µm/m·K6.4 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
620°C1,148 °F

Min Service Temperature

-20°C-4 °F
-30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
3.8 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 µΩ·in
4.5×10⁻⁷ Ω·m17.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.65 V
—

Corrosion Resistance

11 / 100
30 / 100

Manufacturability

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

Machinability

60 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
50%

Weldability

55 / 100
45 / 100

Formability (cold)

45 / 100
10 / 100

Castability

35 / 100
70 / 100

Brazeability / Solderability

65 / 100
40 / 100

Same in both: Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

40 L/kg4.8 gal/lb
55 L/kg6.6 gal/lb

Typical Recycled Content

25%
80%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

71 kN·m/kg
84 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.6 MN·m/kg

Modulus of Resilience

263 kJ/m³
489 kJ/m³

Thermal Diffusivity

13.1 mm²/s
9.8 mm²/s

Thermal Shock Resistance Index

11
9

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 scale35#A356 Grade 8

Manufacturing and finishing

Capability35#A356 Grade 8
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$ Budget$$$ Premium
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

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

35# vs A356 Grade 8 — frequently asked

Is A356 Grade 8 stronger than 35#?

Yes. A356 Grade 8 has a typical yield strength of 450 MPa (65.3 ksi) against 330 MPa (47.9 ksi) for 35# — about 36% more. Tensile strength is 655 MPa (95 ksi) vs 560 MPa (81.2 ksi).

Which is cheaper, 35# or A356 Grade 8?

35# is the lower-cost material: it sits in the budget tier ($) while A356 Grade 8 is premium ($$$). 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, 35# or A356 Grade 8?

35#. Its machinability rates good (60/100) against fair (45/100) for A356 Grade 8; for welding the order is 35# first (good, 55/100) then A356 Grade 8 (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 35# and A356 Grade 8 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.