Router Bearing Replacement

[George Bokros]

I have a frozen router bit bearing. The bearing measures 1 1/4" OD 5/16" ID and 3/16" T. The closest replacement is 1 1/4" OD 8 mm ID and 5 mm thick. This bit is part of a tongue and grove cutting set. I know the OD and thickness (I don't want to foll with changing shims for thickness) are critical for the tongues and grooves fitting properly. I would replace the bearing on both bits to ensure the OD thickness is identical but I am wondering about the ID. 5/16" = .3125 and 5 mm = .314961, question is this, is .002461 enough of difference in ID to be an issue?

Would you use the new bearings if the ID was that much different?

Thanks

[Dave Cav]

Considering how fast a router bit spins, that sounds pretty loose to me. I think I would keep looking to find one with the correct ID.

[Fred Heenie]

I don't often need to replace a bearing on a router bit but when I do I buy a replacement from the original manufacturer of the bit and for paired bits I replace both at the same time. . ;^)

[George Bokros]

I don't often need to replace a bearing on a router bit but when I do I buy a replacement from the original manufacturer of the bit and for paired bits I replace both at the same time. . ;^)

I would buy the bearings from the same mfg but these are Marc Sommerfeld bits from when he was selling his designed bits through CMT. He has ended that relationship. I am waiting a call from Marc to get his suggestions. I will also contact CMT to see if they can help.

[Prashun Patel]

The bearing affects the depth of the cut, right?
In theory, I'd guess if you changed both the tongue and groove bearings (assuming it's a 2-bit set), the fitting would still be the same.

However, I'd just shop -bay or McMaster to get the right one to be sure.