Improving a homemade counterbore

[@andrewdolinskiatcarpathian]

Hello Clive. As always, interesting and informative. Seeing home made tools being made is especially welcomed. 👏👏👍😀

[@Workshopfriend]

Thank you, Andrew.

[@ambisinisterengineering5242]

Watched the short video. The intersection of the teeth to the main body is a very sharp transition a radius there may help a smaller diameter ball endmill may help reduce the stress riser at the intersecting points, also tilting the devideing head a couple degrees off alignment with the axis when milling the teath will result in a positive rake on the tooth as it meets the gullet. look at the teeth on a holsaw they are ground with a radiused disk and a positive rake angle. Nice project and a great idea thanks for sharing

[@Workshopfriend]

Yes, I agree that a radius would be a major improvement as would positive rake. Hopefully next time I make one I can incorporate your helpful suggestions!

[@jakebronger3568]

I think you will get a better result by hardening in oil and for tempering find your self an electric pie oven, got mine for free, set the temper temp and then you will not over temper your parts. I like your vidios.

[@Workshopfriend]

Thanks for your comments. I just looked up the data for silver steel and for smaller sections like this oil hardening from a higher temperature is an option. I like your suggestion of the oven. Might look out for one!

[@stevewilliams2498]

Do you think the zero top rake contributed to your failure ? Makes for a high tooth loading.

[@Workshopfriend]

Thanks for your suggestion! Yes, that may well be a factor. I also wonder whether swarf got wedged between the cutter and spindle as indicated by an mark on the spindle. I was rushing when it happened and not frequently withdrawing the cutter and carefully brushing away swarf.