i am adapting a lathe chuck 3 " to a jewlers lathe ( Lorche)--read
working on small parts


i want to fit the lathe part ( essentaly a long bolt) with aflange and
a 20mm extension--i ddo not want to machine anything on this item

my plans are to create a bushing out of steel--screw it into the lathe
chuck and drill a hole for the lathe bolt to press fit into the bushing


diameter of the lathe bolt is 10mm

what size hole should I drill for a interference fit--looked on the
web--saw all sorts of formulas to do this but i need just a ball aprk
figure--i am planning of using a carbide bit to do it--( i understand
that the finish of the hole would be clean and polished using this
carbide bit) i do not have access to boreing bars or a reamer

any suggestion really appreciate

tia

peter