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Steel A48 Class 30 vs A842 Grade 450

Steel · grade comparison

Steel A48 Class 30 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 150 MPa (21.8 ksi) for A48 Class 30, about 133% more; tensile strength follows at 490 MPa (71.1 ksi) vs 214 MPa (31 ksi). A842 Grade 450 is the more ductile: elongation 1.5% versus 0.6% for A48 Class 30, and A842 Grade 450 is harder (240 HB vs 210 HB). A842 Grade 450 is stiffer (150 GPa vs 100 GPa) and A48 Class 30 conducts heat better (50 W/m·K vs 36 W/m·K). On the shop floor, A48 Class 30 machines more easily (excellent vs fair) and A48 Class 30 sits in a lower cost tier (budget, $) than A842 Grade 450 (standard, $$).

A48 Class 30Choose it when the part is machined in volume, or when cost is the deciding factor.

A842 Grade 450Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

A48 Class 30 vs A842 Grade 450: properties

A48 Class 30A842 Grade 450

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

100 GPa14.5 Msi
150 GPa21.8 Msi

Shear Modulus

40 GPa5.8 Msi
60 GPa8.7 Msi

Bulk Modulus

69 GPa10 Msi
105 GPa15.2 Msi

Tensile Strength (Ultimate)

214 MPa31 ksi
490 MPa71.1 ksi

Yield Strength (0.2% offset)

150 MPa21.8 ksi
350 MPa50.8 ksi

Elongation at Break

0.6%
1.5%

Compressive Strength

752 MPa109 ksi
950 MPa138 ksi

Shear Strength

276 MPa40 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

97 MPa14.1 ksi
205 MPa29.7 ksi

Fracture Toughness (K_IC)

13 MPa·√m11.8 ksi·√in
25 MPa·√m22.8 ksi·√in

Charpy V-Notch Impact (RT)

3 J2.2 ft·lbf
3 J1.8 ft·lbf

Hardness, Brinell

210 HB
240 HB

Hardness, Rockwell B

95 HRB
99 HRB

Hardness, Vickers

195 HV
250 HV

Hardness, Rockwell C

—
22 HRC

Same in both: Poisson's Ratio 0.26

Physical

Density and transition temperatures.

Liquidus Temperature

1,210°C2,210 °F
1,175°C2,147 °F

Same in both: Density 7.15 g/cm³0.26 lb/in³ · Melting Point (Solidus) 1,150°C2,102 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
36 W/m·K20.8 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11 µm/m·K6.1 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Same in both: Latent Heat of Fusion 220 J/g94.6 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10⁻⁶ Ω·m39.4 µΩ·in
8×10⁻⁷ Ω·m31.5 µΩ·in

Same in both: Electrical Conductivity 2.2 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.6 V

Corrosion Resistance

15 / 100
16 / 100

Manufacturability

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

Machinability

85 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

100%
45%

Weldability

30 / 100
25 / 100

Formability (cold)

5 / 100
3 / 100

Castability

92 / 100
62 / 100

Polishability

35 / 100
45 / 100

Same in both: Brazeability / Solderability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

18 MJ/kg7,739 BTU/lb
22 MJ/kg9,458 BTU/lb

Embodied Carbon (primary production)

1.6 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)

30 kN·m/kg
69 kN·m/kg

Specific Stiffness (E / density)

14 MN·m/kg
21 MN·m/kg

Modulus of Resilience

113 kJ/m³
408 kJ/m³

Thermal Diffusivity

15.2 mm²/s
10.8 mm²/s

Same in both: Thermal Shock Resistance Index 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 scaleA48 Class 30A842 Grade 450

Manufacturing and finishing

CapabilityA48 Class 30A842 Grade 450
Default condition——
Relative cost$ Budget$$ 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.

A48 Class 30 vs A842 Grade 450 — frequently asked

Is A842 Grade 450 stronger than A48 Class 30?

Yes. A842 Grade 450 has a typical yield strength of 350 MPa (50.8 ksi) against 150 MPa (21.8 ksi) for A48 Class 30 — about 133% more. Tensile strength is 490 MPa (71.1 ksi) vs 214 MPa (31 ksi).

Which is cheaper, A48 Class 30 or A842 Grade 450?

A48 Class 30 is the lower-cost material: it sits in the budget tier ($) while A842 Grade 450 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, A48 Class 30 or A842 Grade 450?

A48 Class 30. Its machinability rates excellent (85/100) against fair (35/100) for A842 Grade 450; for welding the order is A48 Class 30 first (poor, 30/100) then A842 Grade 450 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A48 Class 30 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.