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Steel 3310 vs 4320

Steel · grade comparison

Steel 3310 and 4320 are both steel grades. Both yield at about 425 MPa — strength does not separate them. 3310 is the more ductile: elongation 26% versus 22% for 4320. 4320 runs hotter in service (350°C vs 200°C continuous) and 4320 conducts heat better (44 W/m·K vs 33 W/m·K). On the shop floor, 4320 machines more easily (50 vs 40 out of 100) and 4320 welds better (fair vs poor).

3310Choose it when the part is bent, formed or impact-loaded.

4320Choose it when the part sees heat, or when the part is machined in volume.

3310 vs 4320: properties

33104320

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

665 MPa96.5 ksi
640 MPa92.8 ksi

Yield Strength (0.2% offset)

425 MPa61.6 ksi
415 MPa60.2 ksi

Elongation at Break

26%
22%

Reduction in Area

58%
50%

Shear Strength

430 MPa62.4 ksi
415 MPa60.2 ksi

Fatigue Strength (Endurance Limit)

310 MPa45 ksi
300 MPa43.5 ksi

Charpy V-Notch Impact (RT)

110 J81.1 ft·lbf
70 J51.6 ft·lbf

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 187 HB · Hardness, Rockwell B 90 HRB

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,425°C2,597 °F

Liquidus Temperature

1,490°C2,714 °F
1,500°C2,732 °F

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

Thermal

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

Thermal Conductivity

33 W/m·K19.1 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.5 µm/m·K6.4 µin/in·°F
11.7 µm/m·K6.5 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
350°C662 °F

Min Service Temperature

-70°C-94 °F
-60°C-76 °F

Same in both: Latent Heat of Fusion 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Electrical Resistivity

3×10⁻⁷ Ω·m11.8 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

15 / 100
11 / 100

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

40 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
55%

Weldability

25 / 100
40 / 100

Polishability

65 / 100
60 / 100

Same in both: Formability (cold) 45 / 100 · Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

36 MJ/kg15,477 BTU/lb
31 MJ/kg13,328 BTU/lb

Embodied Carbon (primary production)

2.6 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
50 L/kg6 gal/lb

Typical Recycled Content

25%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

85 kN·m/kg
82 kN·m/kg

Modulus of Resilience

441 kJ/m³
420 kJ/m³

Thermal Diffusivity

9.1 mm²/s
11.8 mm²/s

Thermal Shock Resistance Index

9
12

Same in both: Specific Stiffness (E / density) 26.1 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 scale43203310

Manufacturing and finishing

Capability33104320
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$$$ Premium$$$ Premium
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.

3310 vs 4320 — frequently asked

What is the difference between 3310 and 4320?

Steel 3310 and 4320 are both steel grades. Both yield at about 425 MPa — strength does not separate them. 3310 is the more ductile: elongation 26% versus 22% for 4320.

Which is cheaper, 3310 or 4320?

Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 3310 or 4320?

4320, by a small margin. Both rate fair for machinability — 50/100 against 40/100 for 3310; for welding the order is 4320 first (fair, 40/100) then 3310 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 3310 and 4320 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.