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Round Bar Controlled Expansion Alloys Borosilicate Glasses W. Nr. 1.3981

Place of Origin China
Brand Name XUNSHI
Certification ISO9001:2015
Model Number Nilo K
Minimum Order Quantity 20kg
Price Negotiable
Packaging Details Plywood crate
Delivery Time 45-50 days
Payment Terms T/T
Supply Ability 500kg per month

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Product Details
Tolerence ±0.003mm Outer Diameter 0.2-8mm
Wall Thickness 0.015-0.5mm Equal Grades ASTM F15, UNS K94610 (FeNi29Co17), 4J29, 29HК
Forms Of Supply Round Bar, Forging, Wire, Strip, Tube, Pipe, Capillary Density 8.16g/cm3
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thermal expansion nickel


corrosion resistant alloys

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Product Description

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

Element Ni Fe Co
Weight(%) 29 53 17


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.



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

Round Bar Controlled Expansion Alloys Borosilicate Glasses W. Nr. 1.3981 0
Size range 
O.D: 0.20~8mm
Wall thickness: 0.05~1mm

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