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Chevalier surface Grinder U seal


Dec 2, 2015
I'd like to replace the U seal ( shaft ) for one of the hyd. cylinder on my Chevalier Grinder. The shaft diameter is 12.5 mm. I contacted Chevalier, they don't have a replacement part, I contacted the manufacturer of the old seal, its obsolete. I called every where, looked the whole wide web, 12.5 mm does not exist .
I measured the shaft, it is .4914 diameter, is that close enough for a .500 seal, will it be too loose ? I have no knowledge of hyd. seals standards.
Never mind the outer diameter, I can easily machine the receiving part.
thank you


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There are companies that will machine these seals from urethane bar stock. I've had hydraulic vice seals made that were unobtanium.
"Is a rotary shaft seal the same as a linear shaft seal ?"

Sometimes, but not always. If you are subjecting the seal to hot pressurized fluid, with one or more axis of travel with high velocity or rotational speed. You better use the exact dedicated seal.

For your application, the conditions are not too harsh, correct me but is this seal only subjected to hand cranked speed and modest oil pressure? You could use a well fitting seal from a dissimilar application and have no issue. Only that longevity and leakage may be compromised in time and wear.

If you have the liberty of redesigning the encasement component of the shaft and seal, and where 12.5mm seal was nowhere to be found I would have suggested using valve packing cord. Where you wrap the shaft in a spiral of square cord and compresse the packing with a screw to make the seal. It works well for valves, as they are revolved slowly, and the packing can be serviced easily. Though since there are 12.5mm seals as found above. Just find the closest one of the outside diameter.