The first time you sharpen them, the coating has gone, really can't see the point. I only buy HSS CO bits now, they stay sharper longer and last a lot longer.
(05-04-2017, 07:59 AM)Mayhem Wrote: [ -> ]I made up an excel spreadsheet that has all the wire gauge, letter, fractional and metric drills up to 1" / 25mm and the recommended RPM for a variety of materials. I printed it out, laminated it and it hangs next to the drill press.
I found it today whilst looking for something completely different! I've added it to the resources section
HERE