Columbium

Do you need custom fasteners created with Columbium? Since our inception, Elgin Fastener Group has met every challenge of providing Quality, Timely, Cost-effective solutions for specialty fastener applications. Every product is built to your specifications, using your prints if necessary.

Below are the technical specifications of the Columbium Bar Stock we have available to meet your needs.

Niobium, Nb (Columbium, Cb); Cold-Worked

Subcategory: Metal; Niobium Alloy; Nonferrous Metal; Pure Metallic Element

Component Wt. %
Nb 100

Material Notes: Cold-worked applies only to tensile and/or hardness values; other property values are typical of the element. The name niobium is used by chemists but the element is generally called columbium by American metallurgists. Fabrication: good formability, work hardens slowly, cannot be soldered. Joining requires adhesives, rivets, nuts and bolts, or capacitive discharge welding. Applications: used in aerospace applications (i.e. rocket boosters), sodium vapor lamps, and superconductors.

Physical Properties Metric English Comments
Density 8.6 g/cc 0.311 lb/in³
Mechanical Properties
Hardness, Brinell 126 126 Converted from Vickers for 3000 kg load/10 mm ball Brinell test.
Hardness, Rockwell A 45 45 Converted from Vickers.
Hardness, Rockwell B 71 71 Converted from Vickers.
Hardness, Vickers 130 130
Tensile Strength, Ultimate 600 MPa 87000 psi
Modulus of Elasticity 103 GPa 14900 ksi
Poisson’s Ratio 0.38 0.38
Shear Modulus 37.5 GPa 5440 ksi
Electrical Properties
Electrical Resistivity 1.51e-005 ohm-cm 1.51e-005 ohm-cm
Magnetic Susceptibility 2.28e-006 2.28e-006 cgs/g
Critical Magnetic Field Strength, Oersted 2010 – 2110 2010 – 2110
Critical Superconducting Temperature 9.23 – 9.27 K 9.23 – 9.27 K
Thermal Properties
Heat of Fusion 290 J/g 125 BTU/lb
CTE, linear 20°C 7.1 µm/m-°C 3.94 µin/in-°F over the range 20-100ºC
CTE, linear 250°C 7.38 µm/m-°C 4.1 µin/in-°F at 300°C
CTE, linear 500°C 7.61 µm/m-°C 4.23 µin/in-°F
CTE, linear 1000°C 8.52 µm/m-°C 4.73 µin/in-°F
Heat Capacity 0.272 J/g-°C 0.065 BTU/lb-°F
Thermal Conductivity 52.3 W/m-K 363 BTU-in/hr-ft²-°F
Melting Point 2468 °C 4470 °F
Optical Properties
Emissivity (0-1) 0.39 0.39 2000°C
Emissivity (0-1) 0.78 0.78 1350°C

References are available for this material.