It is for that very reason that I discard all my old drills.
John
Philistine.........

I know I'm going to get flack over this but I grind brand new drills.
People say buy good and throw them away but I have quite a unique experience in small drills, last place I was employed at, current job don't count as Gert reckons I'm playing, we used to drill precision holes in wood, by precision I mean 50 thou to a 1/2 thou tolerance and before you skoff, yes it can be done and has been for a 100 years.
But there are no 50 thou drills so we used to have to make them. The result was you learned a lot about what cut best and how to hold tolerances.
Fast forward to today and one of my jobs is making dividing plates, all specials and some have 3,300 holes in them, a normal run will be just less than 2,000 holes 2.5mm, 3 mm and 1/8" are popular sizes.
If I buy good quality Guhring drills I can get 4 plates, about 2,000 to 3,000 holes before the web deteriorates and I get run off or worst a broken drill which is unacceptable, one for quality and two for lost time.
Now if I take a that same drill after one use and grind it 4 facet on a small German Meteor drill grinder I can get 8,000 holes before changing.
This might sound like bullshit but the Meteor and Christian drill grinders are still made today, small enough to fit in a shoe box but a new Christian will set you back 14 grand, yup 14 grand, no misprint. So there has to be a use and demand for them.
Because of lost time, the drill is £1.50, the plate is about the same but some of these plates are on the machine for close to 2 hours, that's 2 hours at commercial rates lost when a drill breaks I now grind every drill straight out of the packet and change them every 4 sets regardless.
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