Molybdenum needle

Molybdenum needle is not a standardized product name and has no single public definition. In practice it covers two families: flow-channel clearing needles for fiberglass and aluminosilicate fiber furnaces, used to clear and guide flow at the discharge and forehearth; and discharge needles for electrostatic precipitation, negative-ion purification and plasma generators. The shapes look similar but duty and acceptance criteria differ completely. Furnace needles must withstand over 1600 °C and retain stiffness without bending or softening; diameters start at a few millimeters, with length set by the operating space. Discharge needles are judged on tip discharge concentration and consistency, with sharp, flat or radiused tips and optional nickel, gold or cast copper-sleeve finishes.

Slim parts are among the harder refractory-metal products to make well: straightness and tip precision must be held while controlling cost. Needles commonly range from Ø1.0–10.0mm and 5–150mm long, with surface finish down to Ra0.25 or better. Like stream mouths and electrodes, they can be supplied as part of a furnace package.

In high-temperature melting and thermal-field systems this part is often used alongside electrodes elsewhere in the line. We recommend selecting them together against furnace structure, assembly method and working temperature to reduce thermal-expansion mismatch between different materials.