C/Bores from old end mills

[olderdan]

As I spent much of my time in the grinding shop I used to make piloted counter bore cutters from old end mills for our jig borer, ok I had access to a universal grinder at the time but I have since made them by off hand grinding and finishing with a toolpost grinder and a home made Dremel type tool for backing them off. There is no great precision required in making this type of cutter after all you are only getting a cap head out of the way. Being HSS they last well and can be touched up with a diamond file. Also easy to make from drill rod in a two lip style.
Here is a pic of the ones I am using at the moment, I have a large box of old end mills etc so I make them up as needed.