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Steel A607 Grade 70 vs A633 Grade C

Steel · grade comparison

Steel A607 Grade 70 and A633 Grade C are both steel grades. A607 Grade 70 is the stronger of the two: yield strength 515 MPa (74.7 ksi) against 385 MPa (55.8 ksi) for A633 Grade C, about 34% more; tensile strength follows at 620 MPa (89.9 ksi) vs 530 MPa (76.9 ksi). In exchange, A633 Grade C is the more ductile: elongation 25% versus 16% for A607 Grade 70, and A607 Grade 70 is harder (185 HB vs 160 HB). A633 Grade C runs hotter in service (400°C vs 350°C continuous). On the shop floor, A633 Grade C machines more easily (good vs fair) and A633 Grade C welds better (82 vs 72 out of 100).

A607 Grade 70Choose it when strength drives the design.

A633 Grade CChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

A607 Grade 70 vs A633 Grade C: properties

A607 Grade 70A633 Grade C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
530 MPa76.9 ksi

Yield Strength (0.2% offset)

515 MPa74.7 ksi
385 MPa55.8 ksi

Elongation at Break

16%
25%

Reduction in Area

45%
50%

Shear Strength

400 MPa58 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
250 MPa36.3 ksi

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

185 HB
160 HB

Hardness, Rockwell B

92 HRB
83 HRB

Hardness, Vickers

195 HV
168 HV

Compressive Strength

—
385 MPa55.8 ksi

Fracture Toughness (K_IC)

—
100 MPa·√m91 ksi·√in

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

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,495°C2,723 °F
1,425°C2,597 °F

Liquidus Temperature

1,520°C2,768 °F
1,505°C2,741 °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

45 W/m·K26 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-30°C-22 °F
-45°C-49 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 9 % IACS · Electrical Resistivity 1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.65 V
-0.62 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

48 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
62%

Weldability

72 / 100
82 / 100

Formability (cold)

48 / 100
62 / 100

Brazeability / Solderability

55 / 100
60 / 100

Polishability

45 / 100
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
40 L/kg4.8 gal/lb

Typical Recycled Content

25%
30%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
68 kN·m/kg

Modulus of Resilience

647 kJ/m³
362 kJ/m³

Thermal Diffusivity

12.2 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

11
10

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 scaleA607 Grade 70A633 Grade C

Manufacturing and finishing

CapabilityA607 Grade 70A633 Grade C
Default condition——
Relative cost$ Budget$ Budget
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.

A607 Grade 70 vs A633 Grade C — frequently asked

Is A607 Grade 70 stronger than A633 Grade C?

Yes. A607 Grade 70 has a typical yield strength of 515 MPa (74.7 ksi) against 385 MPa (55.8 ksi) for A633 Grade C — about 34% more. Tensile strength is 620 MPa (89.9 ksi) vs 530 MPa (76.9 ksi).

Which is cheaper, A607 Grade 70 or A633 Grade C?

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

Which is easier to machine, A607 Grade 70 or A633 Grade C?

A633 Grade C. Its machinability rates good (58/100) against fair (48/100) for A607 Grade 70; for welding the order is A633 Grade C first (very good, 82/100) then A607 Grade 70 (very good, 72/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A607 Grade 70 and A633 Grade C 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.