drill bit question

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Displaced Canadian

Displaced Canadian

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Is there a way to make a drill bit less pointy? When I drill I measure the depth from the shoulder. The tip of the bit is beyond that. Normally this isn't an issue but this time I would like to keep overall depth of the hole to a minimum.
 
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Displaced Canadian said:
Is there a way to make a drill bit less pointy? When I drill I measure the depth from the shoulder. The tip of the bit is beyond that. Normally this isn't an issue but this time I would like to keep overall depth of the hole to a minimum.
Click to expand...


Hi DC. Have you a spare drill bit that size? Grind the base flat with just a small back rake as in a milling cutter. Drill first to get the hole started till the edges start to cut then replace with the flattened drill bit.
Another terminology for what you are trying to do is counter bored.
Hope this helps
Kryn
 
Paul in OKC said:
I agree with the spare bit, made to a flat bottom.
Click to expand...

Only problem with regrinding a drill bit is the fact that the flutes and point will have to be perfectly centered or it will wander and not drill a straight hole. Also if you change the bevel on the bit it will tend to follow the grain. A Forstner bit is the only way to go if you want to drill a straight, flat bottomed, stopped hole. Using an endmill usualy requires a very sturdy drill press or a metal lathe, and a very tightly clamped blank. Jim S
 
If its not real deep and the size of your drill is easily matched with an end mill, that will work. BUt if its not or you dont already have one buying one may be more expensive than you want to go and you may have to wait for the mail if you have to have it shipped to you. If the hole is deeper than a standard end mill, grinding a second drill bit is probably your cheapest solution. CLamp the work so it wont move, drill the pilot hole just short of the final depth. Remove the drill bit but dont move the piece. Grind the tip off flat replace the drill bit, finish drilling the hole. Remove the bit regrind a new tip on it to match the original profile. If your drilling on the lathe its pretty easy to do it that way. Forstner bits are ok if it comes in the size you need to drill.
 
If the hole is not especially deep and a standard size, a router bit in a drill chuck can take out a small amount of material nicely.

(I use round ended ones to make needle cases after rough boring with a drill bit)

the point hole of a Forstner may not be acceptable in some holes -- but a two bit combination will allow the removal of the point from one for cleaning up the bottom of the hole.
 
A lot of good advice already, I'll just toss an idea in here. What about taking a brad point bit and filing off the brad? I don't think you would want to use it to drill the bulk of the hole due to it wanting to wander, but if you were to use a standard pointed bit to get all but the last 1/4 inch or so, then swap out seems like it would work.

If this is a bad idea, somebody PLEASE correct me.

Steve
 
plantman said:
Paul in OKC said:
I agree with the spare bit, made to a flat bottom.
Click to expand...

Only problem with regrinding a drill bit is the fact that the flutes and point will have to be perfectly centered or it will wander and not drill a straight hole. Also if you change the bevel on the bit it will tend to follow the grain. A Forstner bit is the only way to go if you want to drill a straight, flat bottomed, stopped hole. Using an endmill usualy requires a very sturdy drill press or a metal lathe, and a very tightly clamped blank. Jim S
Click to expand...

If you drill with a 'regular' bit first close to depth, then go in with the flat bottom to finish up, you will be good.
 
Drill to the depth you want, or just slightly less than you want, with a regular drill bit and then use a flat end ground to remove the taper at the bottom of the hole. Drill bits can be altered easily and old bits are cheap.
 
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