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.

[Okapi]

A good idea for recycling, and very useful if you like to use hidden heads!
I'm a Ifanger counterbore mills fan and they are very expensive if you want them new, a good alternative.

[Howder1951]

In the machine shop at work, we had one fellow who would turn down the end of a partially softened drill bit to make a specialized counterbore with carbide or ceramic tooling, similar to this approach. Nice post!

[Frank S]

I've made a lot of counter bores out of drill bits on my lathes with tool post grinders then touched up the cut angle manually on a bench grinder

[DIYer]

Thanks olderdan! We've added your Counterbore Cutters to our Machining category,
as well as to your builder page: olderdan's Homemade Tools. Your receipt:

Counterbore Cutters by olderdan

tags: counterbore cutter