Round Rod in PTFE GF15 GR10 2000 mm natural

A round rod in a PTFE compound with glass fiber and graphite gives you a blank to turn plain bearings, bushings, piston rings and seats from. The material is based on ordinary PTFE and keeps the almost total chemical resistance, while the additives push down the creep and raise the wear resistance considerably compared with an unreinforced blank.

The long term temperature is 260 degrees and the material handles shorter exposure all the way down toward minus 200, which opens up cryogenic engineering and liquefied gas. The density is about 2.17 g per cubic centimeter. The fire rating is V0. Against acids, bases, solvents and most industrial gases the resistance is in practice total, which is the reason you pick a PTFE compound instead of a reinforced nylon or acetal.

The glass fiber does the mechanical work, the graphite does the sliding. Fifteen percent glass goes a long way: the creep drops drastically, the compressive strength rises and the dimensional stability over time gets better. Ten percent graphite lowers the friction compared with PTFE filled with glass fiber alone and helps lead heat away from the sliding surface. You get a material that can work at higher PV values than pure PTFE without glazing or melting in the contact.

The round rod format is turned into bushings, bearing sleeves, piston rings, valve seats and compressor rings. Common environments are hydraulics with large load swings, compressors for dry gases where oil is forbidden, and pumps in the chemical industry where a metal part would corrode away. Bearings that have to handle dry running for shorter periods are a classic application, since the graphite lays down a thin transfer film on the mating surface.

Machining is uncomplicated. Sharp carbide tools and moderate cutting speeds give a good surface finish. The glass fiber is abrasive, so count on shorter tool life than with pure PTFE. The material expands more with temperature than metal does, around ten times as much, which is worth building into the tolerance calculation for sliding fits and press fits. Pre-warm blanks that are going to be machined to the same temperature as the workshop if they come straight from storage.

Supplied compression molded or extruded in diameters from finger thick rods up to heavy blanks. When you pick the mating surface, hardened steel or hard chrome with an Ra around 0.4 micrometer is a reasonable guideline. Surfaces that are too smooth give the transfer film nothing to grip, and surfaces that are too rough tear up the sliding layer.

Do you want to talk through bearings, speed and mating surface before you order? Send us your conditions and we will help with the material choice.

In the double length, 2000 mm in natural, the rod is enough for several dry lubricated and dimensionally stable bushings.