W. Nr. 1.3981 Round Bar Borosilicate Glasses and Alumina Type Ceramics Sealing

W. Nr. 1.3981, a nickel-iron-cobalt alloy containing approximately 29% nickel and 17% cobalt. Its thermal expansion characteristics match those of borosilicate glasses and alumina type ceramics. It is manufactured to a close chemistry range, yielding repeatable properties which make it eminently suitable for glass-to-metal seals in mass production applications, or where reliability is of paramount importance.
The magnetic properties of Nilo alloy K are governed basically by its composition and by the heat treatment applied.
The composition of the alloy generally decides the optimum values of the magnetic properties, such as permeability, coercive force and hysteresis loss. The heat treatment given to the alloy will vary these properties between the worst and optimum levels

Equal grades: ASTM F15, Nilo-K,UNS K94610 (FeNi29Co17), 4J29, 29HК

Nomonal chemical composition

Key features

• Controlled coefficient of expansion (which decreases with rising temperature to the inflection point).
• Matches the expansion rate of borosilicate glasses and alumina ceramics.

Applications

Glass to metal seals in applications requiring high reliability or resistance to thermal shock, ie. high power transmitting valves

Typical Thermal Expansion of NILO K

Size range 
O.D: 0.20~8mm
Wall thickness: 0.05~1mm

Tolerance
Out diameter: ±0.003mm
Wall thickness: ±0.005mm
Length: ±0.05mm