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Wearbands & Guide Rings

Wearbands & Guide Rings

Prevents metal to metal contact between piston/rod and bore/gland and absorbs transverse loads. Filled PTFE material gives good load capacity with low friction and stick-slip-free operation. Protects critical sealing lips from contamination and dieseling effects. Cost effective, allows designers freedom in hardware material selection. Higher static loads are permissible.

Technical Description

Teflon® is a plastic that offers high chemical resistance, low and high temperature capability, resistance to weathering, low friction, electrical and thermal insulation, and "slipperiness".

General Properties

Teflon® mechanical properties are low compared to other plastics, but its properties remain at a useful level over a wide temperature range of -100°F to +400°F (-73°C to 204°C). Mechanical properties are often enhanced by adding fillers (see paragraph below). It has excellent thermal and electrical insulation properties and a low coefficient of friction. PTFE is very dense and cannot be melt processed -- it must be compressed and sintered to form useful shapes.

Filled Grades

PTFE's mechanical properties can be enhanced by adding fillers such as glass fibers, carbon, graphite, molybdenum disulphide, and bronze. Generally, filled PTFE's maintain their excellent chemical and high temperature characteristics, while fillers improve mechanical strength, stability, and wear resistance.

Typical Filler Properties

FillerPhysical FormAmount (% Weight)Effect of Filler
Glass Fibers Milled Fibers Up to 40% (also in combination with - graphite, MoS2, and carbon)
  • increased wear resistance
  • increased compressive strength
  • reduced cold flow
  • resistant to organic solvent
  • increased rigidity
Carbon Powder Up to 35% (also in combination with graphite, bronze, and glass)
  • increased compressive strength
Carbon Fibers Milled Fibers Up to 30%
  • increased hardness
  • increased wear resistance
  • improved thermal conductivity
  • good dry running properties
  • electrically conductive at higher filler contents
  • resistant to hydrofluoric acid
Graphite Powder Up to 25% (also in combination with glass, bronze, and carbon)
  • Improved sliding properties
  • Reduced coefficient of friction
  • Improved thermal conductivity
Bronze Powder Up to 60% (also in combination with carbon, graphite, and MoS2)
  • Increased compressive strength
  • Increased hardness
  • Increased wear resistance
  • Improved thermal conductivity
  • Reduced cold flow
Molybdenum Disulfide (MoS2) Powder Up to 5% (also in combination with glass and bronze)
  • Improved sliding properties
  • Increased wear resistance
Stainless Steel Powder Up to 60%
  • Improved thermal conductivity
  • Reduced cold flow
  • Resistant to most chemicals
Polymers Powder Up to 20% (also in combination with inorganic fillers)
  • Increased wear resistance
  • Not abrasive to mating surface
  • For soft mating surfaces
Pigments Powder Up to 2%
  • For coloring (identification)

TEFLON is a registered trademark of DuPont.

Additional material upon request.