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Steel A842 Grade 300 vs A842 Grade 450

Steel · grade comparison

Steel A842 Grade 300 and A842 Grade 450 are both steel grades. A842 Grade 450 is the stronger of the two: yield strength 350 MPa (50.8 ksi) against 230 MPa (33.4 ksi) for A842 Grade 300, about 52% more; tensile strength follows at 490 MPa (71.1 ksi) vs 330 MPa (47.9 ksi). In exchange, A842 Grade 300 is the more ductile: elongation 2.5% versus 1.5% for A842 Grade 450, and A842 Grade 450 is harder (240 HB vs 170 HB).

A842 Grade 300Choose it when the part is bent, formed or impact-loaded.

A842 Grade 450Choose it when strength drives the design.

A842 Grade 300 vs A842 Grade 450: properties

A842 Grade 300A842 Grade 450

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

145 GPa21 Msi
150 GPa21.8 Msi

Shear Modulus

57 GPa8.3 Msi
60 GPa8.7 Msi

Bulk Modulus

101 GPa14.6 Msi
105 GPa15.2 Msi

Tensile Strength (Ultimate)

330 MPa47.9 ksi
490 MPa71.1 ksi

Yield Strength (0.2% offset)

230 MPa33.4 ksi
350 MPa50.8 ksi

Elongation at Break

2.5%
1.5%

Compressive Strength

800 MPa116 ksi
950 MPa138 ksi

Shear Strength

290 MPa42.1 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

140 MPa20.3 ksi
205 MPa29.7 ksi

Charpy V-Notch Impact (RT)

3 J2.2 ft·lbf
3 J1.8 ft·lbf

Hardness, Brinell

170 HB
240 HB

Hardness, Rockwell B

88 HRB
99 HRB

Hardness, Rockwell C

—
22 HRC

Hardness, Vickers

—
250 HV

Same in both: Poisson's Ratio 0.26 · Fracture Toughness (K_IC) 25 MPa·√m22.8 ksi·√in

Physical

Density and transition temperatures.

Density

7.1 g/cm³0.26 lb/in³
7.15 g/cm³0.26 lb/in³

Liquidus Temperature

1,180°C2,156 °F
1,175°C2,147 °F

Same in both: Melting Point (Solidus) 1,150°C2,102 °F

Thermal

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.5 µm/m·K6.4 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Min Service Temperature

-20°C-4 °F
-30°C-22 °F

Same in both: Thermal Conductivity 36 W/m·K20.8 BTU/hr·ft·°F · Latent Heat of Fusion 220 J/g94.6 BTU/lb · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

6×10⁻⁷ Ω·m23.6 µΩ·in
8×10⁻⁷ Ω·m31.5 µΩ·in

Electrical Conductivity

—
2.2 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 16 / 100

Manufacturability

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

Machinability

40 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
45%

Formability (cold)

5 / 100
3 / 100

Castability

65 / 100
62 / 100

Polishability

35 / 100
45 / 100

Same in both: Weldability 25 / 100 · Brazeability / Solderability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

19 MJ/kg8,169 BTU/lb
22 MJ/kg9,458 BTU/lb

Embodied Carbon (primary production)

1.7 kg CO₂/kg
1.9 kg CO₂/kg

Embodied Water

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

Same in both: Typical Recycled Content 90%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

46 kN·m/kg
69 kN·m/kg

Specific Stiffness (E / density)

20.4 MN·m/kg
21 MN·m/kg

Modulus of Resilience

182 kJ/m³
408 kJ/m³

Thermal Shock Resistance Index

7
10

Same in both: Thermal Diffusivity 10.8 mm²/s

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 scaleA842 Grade 450A842 Grade 300

Manufacturing and finishing

CapabilityA842 Grade 300A842 Grade 450
Default condition——
Relative cost$$ Standard$$ Standard
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

A842 Grade 300 vs A842 Grade 450 — frequently asked

Is A842 Grade 450 stronger than A842 Grade 300?

Yes. A842 Grade 450 has a typical yield strength of 350 MPa (50.8 ksi) against 230 MPa (33.4 ksi) for A842 Grade 300 — about 52% more. Tensile strength is 490 MPa (71.1 ksi) vs 330 MPa (47.9 ksi).

Which is cheaper, A842 Grade 300 or A842 Grade 450?

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, A842 Grade 300 or A842 Grade 450?

A842 Grade 300, by a small margin. Both rate fair for machinability — 40/100 against 35/100 for A842 Grade 450.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A842 Grade 300 and A842 Grade 450 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.