Composite Self-Lubricating Bushings
AST’s composite, self-lubricating bushings are made up of one of two basic compositions:
- PTFE-Based Metal-Polymer Materials
- Thermoplastic-Based Metal-Polymer Materials
Lubrication free bushings are used in applications where extreme agitation of parts and the force of friction to wear on parts. These self-lubricating bushings are able to withstand high temperatures and have high load-bearing tolerances.
More about each series is explained below.
PTFE-Based Metal-Polymer Materials
Our metal-backed, PTFE-based (polytetrafluoroethylene) polymer bushing materials have a common structure, consisting of a steel backing bonded to a porous bronze sinter layer. This bronze sinter layer is impregnated and overlaid with the filled PTFE bushing lining. The steel backing provides mechanical strength, while the bronze sinter layer provides a strong mechanical bond between the backing and the bushing lining. This construction promotes dimensional stability and improves thermal conductivity. These PTFE linings offer exceptionally low friction.
Thermoplastic-Based Metal-Polymer Materials
The AST20 Series has a similar structure to the PTFE-based materials described above; but with this series, the bushing lining consists of a filled thermoplastic extruded tape. The AST 20 Sereies are very similar to DX® brand bushings in structure and are often substituted for DX bushings providing better value. These materials are generally designed to operate with marginal lubrication. AST20 is most commonly provided with a uniform pattern of indents in the bushing surface that act as grease reservoirs.
AST’s has nearly 1,400 different bushing models that are made of composite materials and are self-lubricating. They are broken down into the following series. Click on each to learn more:
- AST11 - Bronze backed, Bronze with PTFE Series
- AST20 - Steel Shell with POM Plastic Liner
- AST40 - Steel Bronze with PTFE/Fiber Series
- AST50 - Steel shell, Bronze powder with PTFE fiber
If you need help in selecting the best products for your particular application, please remember that design engineering and application assistance are available from AST as part of our value-added services designed to make your job easier.
Click here to go to our online catalog and product specifier for all of our bushings including free CAD downloads.
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