# Bearings and shafts



## timmytiptoes (7 Jun 2013)

A quick call for advice.

I am building a bandsaw and am looking at the wheel bearings and shafts. I have some shafting material donated by a friend. The shaft is 20 mm diameter, H6 tolerance grade.

I understand that the shaft size should be linked to the tolerance of the bearing to get the fit that you require. Is this something that I need to worry about for this project or can I just buy any 20 mm bearing and the fit will be good enough for my needs.

The shaft will be fixed with the bearing pressed in to a housing on the wheel, if that makes any difference.

Thanks for taking the time to look.

Tim


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## Spindle (7 Jun 2013)

Hi

A 20mm shaft to H6 will be fractionally undersized and as such will fit a 20mm bearing - I would use Loctite bearing adhesive when finally assembling the shaft to bearing.

Regards Mick


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## timmytiptoes (8 Jun 2013)

Thanks for that Mick. I'll bear that in mind (almost a pun there i think).

How tight do you think the fit will be? Am I likely to need a press of some sort to fit the bearing or will the vice/hammer/strong language be enough?


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## Spindle (9 Jun 2013)

Hi

I've realised I'm making an assumption in my reply that you are referring to a ball, (or roller), bearing. If you are intending to use a plain bearing please ignore my advice to glue it to the shaft with Loctite  

If you're intending to use a ball bearing, it should be a fairly easy fit onto the shaft - at most all you should need to do is tap it into place with the aid of a tube which will slide over the shaft and impact the bearing inner race. If its a bit tight put the shaft in the freezer for an hour or so and then assemble as quickly as possible - don't heat the bearing as this may have an adverse effect on it's lubricant.

Regards Mick


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## timmytiptoes (10 Jun 2013)

It will be a ball bearing. I would never have thought of putting the shaft in the freezer. I would do the same if I needed to get my wedding ring off but it wouldn't have occurred to me to try it with steel shaft. Odd how people's minds work (or not)!

Thanks again for taking the time to reply.

All the best.

Tim


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