Bushing Size based on Seal Size Diameter?
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    Default Bushing Size based on Seal Size Diameter?

    I'm trying to replace a bronze bushing that fits on a shaft. The OD of the bushing has been compromised so I do not know the proper OD to order. I have the new double ribbed seal and the spec calls the seal ID as being 1 37/64".
    So if the seal ID is 1 37/64" is this the size OD bushing I need or slightly smaller? How do I determine this?

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    Not uncommon for a seal recess to be larger than the bushing OD......Whats wrong with measuring the bushing bore in the machine?.....I doubt that off the shelf bushings are available in 64th sizes anyway.....Likely have to be custom made.

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    You need to fit the bushing a little tighter than the bore so it stays put .003/5 will work...Phil

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    Seals are typically an “interference” fit over the shaft. I believe the spec given for the seal ID is normally shown as the shaft size to fit it. That looks like it may be for a 40mm shaft (or bushing in your case).

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    The ID of the bushing is at 1 3/8". The height is 3/4".
    The current OD I measured is just over 1 9/16" but it varies due to wear.

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    The only correct way here is to measure the bore the bushing fits ! If you can't buy the correct bushing to fit and need to make one ,make the OD .001-.002 larger. And most likely the ID will need to be finished to size after installation .also look at McMaster-Carr for a stock bushing of the requited size shorten if needed.

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    Do yourself a favor and start measuring this setup with metric numbers in mind. You don't say what type of equipment you're working with, but most seals, bearings, ball, bronze or otherwise are metric. Even here in the US. But still we'll all talk about "fits" in thousandths. Hard habit to break, as those are the type of numbers we see in our minds.

    Just know that if you have say a 2 thou press fit of the bearing into the housing bore, that same amount is going to show up as shrinkage on your ID, and can easily lead to the need for working the ID after the fact, or the need to account for it before the fact. Just sayin...

    A seal ID is not much to go on, as it is slightly compressed in use and difficult to measure with any certainty. There should be numbers on the old seal. Likely all metric. Go with them if you can read them. But like the one responder said, the seal bore and bearing bore can easily be two different sizes.

    Ha... I see I just repeated a bit of what John Evens said. So yes, definitely things to consider in your quest.

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    Re metric ;-FYI

    1 37/64'' = 1.5781'' or 40.084 mm

    40mm = 1.5748'' ....or a difference of 0.0033''

    Therefore I suspect ??? the od of that seal is meant for a 40mm bore

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    You are working on this kinda backwards.The seal id should be what rides on the shaft not the bushing. The shaft od is the bushing id plus clearance. The bushing od is the housing id plus whatever interferance for a press fit. Whatever brand seal you have the manufacturers all have online catalogs that will give you the housing and shaft sizes for that seal. Not knowing exactly what kind of seal you have hard to guess what sizes it is designed for.

    So if the bushing od is messed up then you should be checking the housing to see if it is round and if it is not then you have to correct that first as that will determine what shape the bushing id will be.

    Symmco makes all kinds of sintered bronze bushings in inch and metric sizes and is available from Motion Ind or Applied or just about any industrial supplier.They also have an online catalog.

    I encounter that problem often and I first clean up the housing,if there is enough meat there I generally go to the next od size or just get the next od size and machine it to fit.

    The Symmco bushings are sized with the correct press fit on the od; the inch or metric will be larger than the nominal housing size for press fit and the id is larger so it will crush to the correct id. So usually there is no need to ream them.


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