Nickel 205 & 270 Properties, Applications, and Specifications

UNS N02205, Grade 2, UNS N02270, Grade 4

Nickel 205 and Nickel 270 are two commercially pure nickel grades chosen for electrical, electronic, and high-purity applications where chemistry, magnetic behavior, and thermal performance all need to be controlled. As a Nickel 205 and Nickel 270 supplier serving aerospace, defense, medical, and semiconductor manufacturers, EFINEA has consolidated property data, applications, chemistry, and specifications on this page so engineers can evaluate both grades from one place. 

EFINEA stocks both grades in rod and bar, with Nickel 205 also available in sheet, strip, and wire from standard stock; Nickel 270 sheet, strip, and coil are available upon request through select mills. For questions about whether Nickel 205 or Nickel 270 fits your design, our sales engineers and metallurgists are reachable at 800-348-6268.

Nickel 205 & 270 Applications

Commercially pure nickel grades are specified when an application requires predictable electrical, magnetic, and thermal behavior that more heavily alloyed nickels can’t provide. Both Nickel 205 and Nickel 270 are used in electron tubes, semiconductor packaging, battery components, and other parts where chemistry control is the primary design constraint.

Nickel 205 Applications

Nickel 205 is the workhorse grade for electron device fabrication. Common end uses include anode plates for vacuum devices, electron tube grids, transistor enclosures, lead-in wires, and components in glass-to-metal sealing assemblies. 

The grade also performs well as a substrate for nickel plating operations and as a cathode material in industrial electrochemical cells. Its combination of controlled chemistry and predictable thermal behavior supports the close tolerances these parts require during repeated thermal cycling.

Nickel 270 Applications

Nickel 270 is chosen specifically when residual elements would interfere with device behavior. Hydrogen thyratrons rely on it because trace impurities would alter gas absorption and emission characteristics. Electrical resistance thermometers use it because the resistivity-to-temperature relationship is more predictable in a high-purity matrix. 

Nickel 270 also serves as a substrate for precious metal cladding, since the underlying nickel needs to be free of contaminants that could diffuse into the clad layer during processing.

Common Applications Using Nickel 205 & Nickel 270

Across both grades, recurring applications include:

• Anode plates for electron tubes and vacuum devices
• Battery plaques used as porous substrates in sintered-plate batteries
• Cathode shanks for industrial electroplating cells
• Electron tube cathodes, where low-impurity nickel supports stable thermionic emission
• High-temperature electrical leads in instrumentation and sensors
• Magnetostrictive devices, including ultrasonic transducers
• Passive cathodes in electrochemical and electronic assemblies
• Plater bars used as anode supports in plating operations
• Semiconductor packaging cans and lids requiring controlled outgassing
• Transistor enclosures where hermetic sealing and dimensional stability matter

For broader background on the engineering and materials applications above, IEEE remains a useful reference for the underlying device physics.

Nickel 205 Properties

Mechanical and physical properties drive grade selection more than any other factor. The data below reflects typical room-temperature behavior for Nickel 205 in standard wrought forms. Variations of a few percent are expected based on form, finish, and processing history.

Nickel 205 Physical Properties

Density, Curie temperature, melting point, electrical resistivity, thermal conductivity, specific heat, and thermal expansion are the values most often referenced during component design. Curie temperature is particularly relevant for parts that switch between ferromagnetic and paramagnetic behavior across an operating range, and the 360°C value for Nickel 205 sits well above most electronic operating envelopes.

Nickel 205 Typical Mechanical Properties

Mechanical values shown reflect annealed condition material at room temperature. Cold work increases tensile and yield strength while reducing elongation, so finished part properties will depend on the processing history of the form supplied.

Nickel 270 Properties

Nickel 270 is a 99.97% high-purity nickel produced by powder metallurgy and worked into standard wrought forms. Because residuals are held roughly an order of magnitude lower than Nickel 205, several property categories shift, particularly electrical resistivity at cryogenic temperatures and behavior under elevated-temperature exposure. Mechanical properties depend strongly on form and condition, so multiple data sets are presented. 

Nickel 270 Typical Physical Properties

Nickel 270 Typical Mechanical Properties

Modulus of elasticity and Rockwell B hardness values give a starting point for stiffness-driven and wear-driven part selection. As with Nickel 205, cold-worked material shows substantially higher strength and lower elongation than annealed material.  

Nickel 270 Typical Tensile Properties & Hardness

Form and condition matter substantially. Cold-rolled strip can exceed 600 MPa tensile strength with hardness above HRB 90, while annealed rod and sheet sit closer to 345 MPa and HRB 30 to 40. Specify the form and condition needed for the application before placing an order.  

Nickel 270 Thermal & Electrical Properties

This is the most important reference table for engineers designing parts that operate across a wide temperature range. Mean linear expansion, thermal conductivity, and electrical resistivity all shift with temperature, and the expansion data is referenced from 21°C (70°F). The resistivity climbs from 6.6 nΩ·m at -196°C to over 500 nΩ·m at 1093°C, affecting calculations for resistive elements, high-temperature interconnects, and any part where ohmic losses matter.

Nickel 205 & 270 Chemistry

Chemistry is what separates these two grades and what makes each one suited to specific applications. The table below shows the maximum allowable residuals under ASTM F3 for each grade.

Several differences are worth calling out. Iron, manganese, silicon, and sulfur are held an order of magnitude lower in Nickel 270 (0.001 to 0.005% maximum) than in Nickel 205 (0.005 to 0.30% maximum). Chromium and cobalt are also controlled in Nickel 270 but are not specified for Nickel 205. The magnesium range in Nickel 205 (0.010 to 0.08%) is an intentional addition rather than a residual; magnesium scavenges sulfur and improves hot workability and high-temperature ductility.

Nickel 205 & 270 Specifications

Both grades are supplied to ASTM F3, the standard specification for nickel alloy electron device, cathode, and general-purpose wire material.

When sourcing material, reference both the ASTM grade and the UNS number to avoid ambiguity. For additional standard references, ASTM International and ASM International publish the original technical standards and reference handbooks behind the data on this page. 

Sourcing Nickel 205 and Nickel 270 From EFINEA

EFINEA stocks Nickel 205 and Nickel 270 in standard wrought forms, including rod, bar, sheet, strip, plate, and wire. Standard stock typically ships within 24 hours of order confirmation, and every shipment includes mill certification with heat and lot numbers, chemical composition data, mechanical property results, and dimensional inspection where applicable. As a Nickel 205 and Nickel 270 supplier, operating under AS9100D and ISO 9001:2015, EFINEA supports prototype quantities through full production runs for aerospace, defense, medical, electronics, and industrial customers.

To request a quote or check current availability, contact the EFINEA sales team at 800-348-6268 or Sales@efineametals.com. Data sheets for both grades are available in the Technical Library.

Frequently Asked Questions About Nickel 205 & Nickel 270