Do REALLY need Imperial ER25 collets?
One of the advantages of the ER collet, is thatm being slit from both ends, each collet (Except for the very small ones ) has a range of 1 mm. Thus enables them to grip Metric or Imperial , or in between sizes,.
I have bee using my ER25 collets in this way, to hold millinbg cutters, or work, for probably 30 years or more.
Howard