DU Type Bushings & Washers

High-Performance Three-Layer Dry & Boundary-Lubricated Oil-Free Self-Lubricating PTFE Composite PAP Bush

DEV PRECISION ENGINEERS manufactures and exports premium-grade DU and DUB Type Self-Lubricating PAP Bushings engineered to deliver exceptional dry-bearing performance. Sold under our trusted “Dev Engine Spares” brand, these oil-free bushings combine the outstanding low-friction properties of Polytetrafluoroethylene (PTFE) with structural steel strength, high thermal conductivity, and low thermal expansion.

Three-Layer Bonded Composite Structure

Our DU type bushings are built using a precision multi-layer composition designed for maximum durability and low static/dynamic friction:

Layer Breakdown & Specifications:

  • PTFE / Lead Bearing Overlay ($0.01\text{ mm} – 0.03\text{ mm}$): Provides an exceptionally low friction coefficient, acting as a self-lubricating transfer film during initial break-in.
  • Porous Sintered Bronze Matrix ($0.2\text{ mm} – 0.3\text{ mm}$): Interlocked firmly with the steel backing, this layer absorbs and retains the PTFE mixture while providing excellent thermal conductivity.
  • Steel / Bronze Backing Strip ($0.7\text{ mm} – 2.3\text{ mm}$): Imparts high load-bearing capacity, structural rigidity, and dimensional stability.
  • Surface Plating: Anti-corrosion outer finish available in Tin-plating ($0.005\text{ mm}$) or Copper-plating ($0.008\text{ mm}$).

Movement Suitability & Operational Advantages

DU Type PAP Bushings are designed primarily for applications involving:

  • Rotating Movements
  • Oscillating Movements
  • Reciprocating Movements
  • Sliding Movements

Key Performance Features:

  • Oil-Free / Dry Operation: Ideal for environments where regular lubrication is difficult, impossible, or undesirable.
  • Low Friction Coefficient: Exhibits minimal static and dynamic friction, preventing stick-slip issues.
  • Superior Wear Resistance & Heat Dissipation: Porous bronze and steel backing rapidly conduct frictional heat away from the sliding interface.
  • Low Thermal Expansion: Maintains tight clearances and structural accuracy under fluctuating operational temperatures.

Primary Applications & Industries Served

Our self-ranging DU PAP bushings provide reliable, maintenance-free service across diverse global industries:

  • Automotive & Commercial Vehicles: Tractors, combines, crop sprayers, earth-movers, graders, construction machinery, power steering cylinders, steering gear thrust washers, disc brake calipers & pistons, shock absorbers, governor linkages, windshield wiper motors, tilt gear assemblies, struts, and shock absorber guide bushings.
  • Hydraulics & Industrial Valves: Hydraulic cylinders, gear pumps, motors, axial/radial piston pumps, vane pumps, plunger pumps, ball valves, butterfly valves, and poppet steam valve trunnions.
  • Business & Office Machines: Photocopy machines, typewriters, mail sorters, postage meter systems, computer terminal printers, peripheral equipment, automatic printing devices, and mail processing machinery.
  • Home Appliances: Tape recorders, refrigerators, air conditioners, vacuum cleaners, floor polishers, sewing machines, ovens, dishwashers, and clothes washing machines.
  • General Industrial Equipment: Materials handling systems, marine engines, packaging machinery, textile equipment, and industrial tools.

Technical Resources & RFQ Options

Custom Sizes & Inch/Metric Requirements Available

We supply DU Type PAP Bushings in standard metric and inch sizes, as well as custom dimensions tailored to your drawing specifications. Contact our export sales team for bulk inquiries.