Tests show the products can be used without external lubrication at higher pressures and speeds than possible with many other materials. Solid-lubricant insert bearings are used in applications that are difficult to lubricate or have dry start-up conditions. Base materials such as aluminum bronze and manganese bronze are limited to relatively light loads because holes required for the inserts compromise strength. Steel has enough strength but can gall when loaded joints are stationary or oscillating. Graphite-plug bearings with ToughMet base material combine strength with low friction, making it a solution for these applications. ToughMet bearing material is used in equipment such as excavators, haulage trucks, continuous miners, and tractors.
