"Ignoramus14507" wrote in message
...
I am looking at two 6204 bearings at McMaster-Carr. One is a regular
double sealed bearing 5972K45 for $7.72. Another is a "PermaLube"
bearing 2349K423 that costs $15.32. According to McMaster, perma-lube
bearings are permanently lubricated and require no maintenance.

But what about the regular bearing 5972K45? If it is double sealed, it
must also have lubricant inside, already? What is different about these
Perma-Lube bearings?

i

Bearings are interesting. While some bearings look alike they can be very
different.

If you have a bearing supplier near you I would go there and ask the
question in person, describing your application.

For instance the bearings used on a surface grinder are a whole lot more
critical than the bearings used on a drill press and the drill press
bearings are a whole lot more precise than something you find on a skill
saw.

The lubrication gets tricky, too much grease, the wrong kind of grease can
kill a bearing. and The speed the bearing is run and the load it carries is
also a factor. The good thing is the bearing companies have really great
catalogs with a lot of technical info and the bearing places are usually
happy to part with them. Also it has been my experience that the folks at
the bearing houses know their stuff, so it is a pleasant change from the big
box places that have clerks that are likely to know very little.

--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.