TEF-MET® is one of the most common bushing materials used worldwide due to its numerous advantages. Due to its thin wall thickness even at bigger diameters, it can be easily used for applications that do not allow a lot of bearing space, yet it delivers a very high load capacity as well as one of the lowest friction values among all bushing materials – and still being maintenance-free!
TEF-MET® belongs to the family of wrapped bushings or split bushings. It is produced according to a DIN standard meaning that the ID and OD and its tolerances are fixed to an international standard. The bushings are manufactured from a plate material, which consists of a backing material, in this case steel. It is coated with PTFE in a sintering oven using bronze powder as a bonding agent between the PTFE and the steel. The sintered bronze plays a very important part for this material as without it, the PTFE would easily peel off from the backing material.
After the sintering process, the raw material plates will be rolled (calibrated) to the right thickness. There are only 6 different thicknesses for this material (0.75, 1, 1.5, 2, 2.5 and 3 mm). Then these plates will be cut to the right rectangular size for the bushing. Firstly, it will be roughly rolled into a round shape, followed by the calibration with tools consisting of a housing and a shaft. The plain bearing is then pressed into the housing and the shaft is pushed all the way through calibrating the bushing to the right size and making it completely round. The last step is to tin coat the bushings for corrosion protection.
It is very important to understand that due to the split, wrapped bushings can NEVER be properly measured in a free state unlike solid machined bushings! A split bushing can ONLY be measured after it is pressed in a housing with the right tolerance of H7. The bushing ID has to be a H9 AFTER pressing in and the shaft will have to have a F7 or H8 tolerance.
The disadvantage for this bearing material is that the PTFE is relatively prone to scratches and therefore it should not be used in applications that are abrasive and full of dirt.
TEF-MET® can be produced from an ID of 3mm all the way up to 400mm