# Determining Milling Machine Taper...?



## IC... (Sep 13, 2018)

I have found a local milling machine for sale.  It runs but it has no tooling, no chuck and no manual.  How can I tell if it has an R8, MT2, MT3 or something other taper?

Thanks for your help.... I am new to this stuff.


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## Tom O (Sep 13, 2018)

I would think the owner would know or if you know the make / model you can google.


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## Dabbler (Sep 13, 2018)

MT3/R8:  the opening will be either approx 1" (MT3) or 1.5" (R8)  in the unlikely event of cat30/cat40, someone else here will have to answer.  the taper on R8 is also much more abrupt.

Mt2 will have about an .800 opening (a little bigger than your thumb)


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## IC... (Sep 13, 2018)

Awesome!  That helps a lot


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## Alexander (Sep 13, 2018)

There is also the dreaded BS#9 that is smaller than mt3 and bigger than mt2. It would help to have a machinist friend look at it. R8 or 40 taper are great for garage use.


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## Dabbler (Sep 13, 2018)

I forgot about that Alexander!  great advice!  I prefer R8, but it is what I've always used...


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## PeterT (Sep 13, 2018)

I was hoping to find a link with 1:1 scale drawings just to roughly eyeball. No luck but this should provide an overview.
https://en.wikipedia.org/wiki/Machine_taper
As Alex says, best you have a buddy with machinery experience or a known shank that fits from which you can measure. Hopefully its not too obscure. If so, consider the cost/availability of tooling might outweigh a deal on a machine. Small mills might have MT. Probably most common is R8 until you get into bigger or more industrial machines.


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## IC... (Sep 13, 2018)

Sadly, I do not have any machinist friends.  I think I am safe from the BS#9.  I suspect it is R8 but will check it out tomorrow if I can.  The diam. is definitely larger than 1 inch.  I did not feel the taper angle change one would expect with an R8 but who knows.


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## IC... (Sep 13, 2018)

It is a smaller machine... RF-25 equivalent I think.

I found some diagrams a little earlier and reviewed the wiki page which was great for the morse tapers.


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## PeterT (Sep 13, 2018)

This link has some legacy machines of older era. Less so on Asian machines & their clones. If you can provide a pic, that might help. Not by me, but maybe somebody 
http://www.lathes.co.uk/


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## RobinHood (Sep 14, 2018)

Hi IC..., if it is a RF-25 or clone, then you probably have a R8 taper. See below.






As stated before, take a picture of the data tag (or write it down) then google it or post here and someone will help you out ( if it has a data tag...). Or take a picture of the spindle bore and post it. People will be able to at least tell the difference between a Morse taper and a R8 taper. R8 has an anti rotation pin inside (assuming it is not busted off) about 1.5 inch from the mouth of the spindle. If it is Morse, it will be completely smooth all the way.


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## Bofobo (Sep 14, 2018)

A community of machinist friends at the click of a button


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## IC... (Sep 16, 2018)

It has been a very helpful community so far!


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