Product Description

This listing is for 4 piece/s.

SKF PTFE composite bushings are self-lubricating as well as maintenance-free and due to their low friction provide a long service life. Despite of their compact design, they can accommodate heavy radial loads and are suitable for relatively slow rotational or oscillating movements. They also have good dimensional stability and thermal conductivity.

PTFE composite bushings consist of a sheet steel backing on which a 0.2 to 0.4 mm thick porous layer of tin/bronze is sintered. Furthermore, by a rolling process the pores of the sintered layer are filled with a mixture of PTFE (polytetrafluoroethylene) and molybdenum disulphide additives. This additional 5 to 50 m thick running-in layer provides an optimum combination of the mechanical properties of the sintered tin/bronze and the good sliding and lubricating properties of the PTFE mixture.

Running-In Period

During a short running-in period, minute amounts of the PTFE material from the running-in layer are transferred to the counter surfaces. After this transfer has taken place, the characteristics low friction and wear properties of these bushings are reached.

Lubrication:

The PTFE-based sliding surface permits smooth, low-friction operation without lubrication. The presence, or continuous supply of oil or other non-corrosive fluids may be advantageous and improve the performance of these bearings.

Specifications:

• Dimension Standards: ISO 3547-1:2006 (with a few exceptions).
• Tolerances:
  • Outside diameter D: ISO 3547-1:2006.
  • Checking Values: ISO 3547-2:2006.
• Materials: Steel backing with a layer of sintered tin/bronze, pores filled and covered with a running-in layer of PTFE with molybdenum disulphide additives.
• Permissible Operating Temperature Range: -200 to +250°C (-330 to +48-°F).
• Chemical Properties:
  • Steel backing and sintered tin/bronze layer are the primary factors in determining the chemical resistance of SKF composite plain bearings, as the sliding (covering) layers are resistant to most chemicals. The covering layer is virtually inert because of its PTFE content, although at increasing temperatures molten alkali metals and free fluorine attack it.
  • At room temperature the sintered tin/bronze structure has good resistance to sea water, steam, atmospheric influences, salt solutions and sulphuric acid, but not to oxidizing acids or media containing ammonia.
  • All exposed surfaces of the steel backing are electrolytically tin-plated but this provides only limited protection against corrosion in most applications. In cases where the bushings are to be exposed to corrosive media, or where there is a risk of corrosion in the contact between the steel backing and the housing material, the backing can be protected by a nickel, chromium or zinc coating applied electrolytically.

  Main Applications:

  SKF PTFE composite dry sliding bearings are suitable for applications where there are heavy loads and where a sliding material with self lubricating properties is a prerequisite. Applications include:
  • Automotive.
  • Material handling equipment.
  • Home appliances and consumer goods.
  • Textile machinery.