Ball Bearings 38Z vs 608Z question

[11b30b4]

I am rebuilding a vintage Craftsman Belt Sander and the original bearings are SFK 38-ZZ on one side and SKF 38-Z on the other side. The bearings measure 8mm bore x 22mm OD x 7mm thick.

Motion Industries

www.motionindustries.com

Searching for replacements came up with 608-zz bearings with the same measurements.

SKF

www.skf.com

My question is:

Are these two bearings the same but with different model numbers or is there difference in how these bearings work and for different applications?

 

[CallumRD1]

Normally a -Z bearing will have a metal shield on one side while a -ZZ will have a metal shield on both sides. -2RS would have rubber seals on both sides.

As long as the speed range those bearings will see is within the correct range for the replacement bearing, I'd substitute -2RS sealed bearings that will keep grit and dust out. They don't ever need lubrication and should last far longer than a shielded bearing in a dusty environment.

 

[seber]

Specs are nearly identical. The 608 is and update of the 38 with slightly better tolerance. I wouldn't give it a second thought.

 

[The Cobbler]

I'm X2 on the normally a zz is shielded both sides & z is only 1 side and to replace with 2RS

 

[11b30b4]

Thank you all for the recommendations and information.