Description for Two Types of Non-sag Tungsten Wires

Non-sag tungsten wire
Non-sag tungsten wires which have been doped with trace amounts of potassium have an elongated interlocking grain structure with non-sag properties after recrystallization. Non-sag tungsten wires are produced in sizes from less than 0.02mm up to 6.5mm in diameter and are used largely for lamp filament and wire filament applications.

Thoriated tungsten wires
Introduction Tungsten wires containing thoria particles are suitable for various electron tubes, vibration-resistant bulb filaments and TIG welding electrodes. Alloyed thorium enhances the emission of thermions by lowering the work function barriers. In addition, thoriated tungsten wires are difficult to deform as the mechanical properties of thoriated tungsten wires are improved because thoria particles have a dispersion strengthening effect.

Types and properties

Types	Properties
W51	W51 wires have excellent non-sagging properties and are tough against vibration. 0.7% thoria containing tungsten.
W53	W53 wires have excellent electron emission properties and are tough against high-temperature deformation. 1.0% thoria containing tungsten.
W54	W54 wires have excellent electron emission properties and are tough against high-temperature deformation. 1.7% thoria containing tungsten.
W56	W56 wires have excellent electron emission properties and are tough against electrode abrasion. 2.0% thoria containing tungsten.