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Steel Super Invar-ANN vs Super Invar-CD

Steel · Super Invar temper comparison

Super Invar-ANN and Super Invar-CD are two conditions of the same steel grade, Super Invar: ANN (annealed) versus CD (cold drawn). The chemistry is identical, so every difference below comes from the condition. Super Invar-CD is the stronger of the two: yield strength 570 MPa (82.7 ksi) against 300 MPa (43.5 ksi) for Super Invar-ANN, about 90% more; tensile strength follows at 680 MPa (98.6 ksi) vs 500 MPa (72.5 ksi). In exchange, Super Invar-ANN is the more ductile: elongation 35% versus 12% for Super Invar-CD, and Super Invar-CD is harder (210 HB vs 150 HB). On the shop floor, Super Invar-ANN welds better (very good vs good).

Super Invar-ANNChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

Super Invar-CDChoose it when strength drives the design.

Super Invar-ANN vs Super Invar-CD: properties

Super Invar-ANNSuper Invar-CD

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

145 GPa21 Msi
150 GPa21.8 Msi

Tensile Strength (Ultimate)

500 MPa72.5 ksi
680 MPa98.6 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
570 MPa82.7 ksi

Elongation at Break

35%
12%

Reduction in Area

60%
45%

Compressive Strength

310 MPa45 ksi
590 MPa85.6 ksi

Shear Strength

340 MPa49.3 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
300 MPa43.5 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

130 J95.9 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

150 HB
210 HB

Hardness, Rockwell B

80 HRB
95 HRB

Hardness, Vickers

155 HV
220 HV

Same in both: Shear Modulus 57 GPa8.3 Msi · Bulk Modulus 110 GPa16 Msi · Poisson's Ratio 0.28

Physical

Density and transition temperatures.

Same in both: Density 8.15 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,450°C2,642 °F

Thermal

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

Thermal Expansion (CTE, 20–100 °C)

0.5 µm/m·K0.28 µin/in·°F
0.7 µm/m·K0.39 µin/in·°F

Same in both: Thermal Conductivity 10.5 W/m·K6.1 BTU/hr·ft·°F · Specific Heat Capacity 515 J/kg·K0.12 BTU/lb·°F · Max Service Temperature (continuous) 150°C302 °F · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.2 % IACS · Electrical Resistivity 8×10⁻⁷ Ω·m31.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 28 / 100

Manufacturability

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

Machinability

30 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
35%

Weldability

70 / 100
60 / 100

Formability (cold)

75 / 100
40 / 100

Same in both: Brazeability / Solderability 70 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 75 MJ/kg32,244 BTU/lb · Embodied Carbon (primary production) 5.5 kg CO₂/kg · Embodied Water 130 L/kg15.6 gal/lb · Typical Recycled Content 25%

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 scaleSuper Invar

Super Invar-ANN vs Super Invar-CD — frequently asked

Is Super Invar-CD stronger than Super Invar-ANN?

Yes. Super Invar-CD has a typical yield strength of 570 MPa (82.7 ksi) against 300 MPa (43.5 ksi) for Super Invar-ANN — about 90% more. Tensile strength is 680 MPa (98.6 ksi) vs 500 MPa (72.5 ksi).

Which condition does FabDigit quote by default, ANN or CD?

ANN is the default Super Invar condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, Super Invar-ANN or Super Invar-CD?

Super Invar-CD. Its machinability rates fair (35/100) against poor (30/100) for Super Invar-ANN; for welding the order is Super Invar-ANN first (very good, 70/100) then Super Invar-CD (good, 60/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Super Invar-ANN and Super Invar-CD 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.