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Metric class of fits

KevinB

Aluminum
Joined
Jan 8, 2010
Location
Arizona, US
I find the metric system very easy to use, I wish we would of went all metric years ago. My problem is from time to time I get European drawings with a whole different set of callouts for everything from materials to class of fits. How can I find out exactly what the different class of fits are? For example a diameter of 30.9 T6 or 10 H6. I can figure out what + or - .05 is, but how do you figure out class of fits. I have searched on the WEB and found charts and graphs and still can't quite figure it out. I should have went to MIT a long time ago so I could have figured this out. Can't I just multiply something by 10 a get a good answer.

Does anyone know any place to go on the WEB or an easy way to get correct tolerances.

Thanks in advance Kevin :willy_nilly:
 
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Number of the tolerance means how wide is the tolerance area. Letter defines where the tolerance area is located to the nominal dimension.

For example, H7 fit for 18-30mm shaft is +0 -0.021mm, whereas F7 is -0.020 -0.041mm. The tolerance is equally wide on these, but F7 is intended for looser fit.

It takes some time to get used to these, but these are really easy for engineers. They can use the same tolerance on any diameter to get the same type of fit.
 
Search passungsrechner.xls via google.

There are two fields, one is for standardized holes, one for standardized shafts.

Höchstmaß gives you the upper end, Mindestmaß gives you the lower one. Maßtoleranz shows you the witdh of the tolerance, upper minus lower end.
In case you have to do this more often, aks one of the guys who gives you the metric prints to supply you with a "Tabellenbuch Metall." There, the stuff is fund in tabulated form.

In caser you have questions concerning the Spreadsheet, feel free to PM me.

Cheers,
Johann
 








 
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