I have ordered an ER16 extension shaft, whose shank is 16mm dia x 150 long to use as an auxiliary spindle.
Googling for 16 ID ball bearings brings up all sorts of crud ranging from 15mm bore, through 5/8 inch to the 'ubiquitous' 6203. And thereby hangs the tale - some sites list the 6203 as 5/8 bore, at least one declares it to be 16mm and most state 17mm bore.
Please, what is the ID of a 6203 bearing?
Or, if/when all else fails, can you suggest how best to machine the shaft down to a standard bearing-size without loosing too much accuracy/runout etc. (I would prefer Metric but beggars can't be choosers.)
Regards,
Geoff,
Thailand