Forstner Longevity

[avengers63]

It seems that the forstner bit I use to hog out the cavities may be getting dull. How long do yours tend to last?

Also, has anyone ever used a Drill Doctor to sharpen their bits? If so, how 'bout some input. Woud it work on a Forstner, or only a "normal" drill bit?

[Prostheta]

Buy quality bits, and don't let them get too hot or they'll lose their ability to hold sharp edges or have new ones sharpened in. Mine last until I need a new one.

[Quarter]

For hogging out, I have a cheep set of Harbor Freight bits and use a needle file for sharpening.

For the precision work, I have a set of Freud's and if you treat them nice, its a long time between sharpening.

[ihocky2]

Drill doctors won't work on a forstner or brad point bit. I haven't had to sharpen my brad points yet, so I don't know how bad thsoe are, but forstners are easy. I just use a small fine cut traingular file. Lay the file flat on the surfaces and file off a little. It usually doesn't take much metal removal to get a nice cutting edge again. I only have a cheap set that I use for hogging out, but it seems my hand sharpening lasts longer than the factory edge. Just hit the large cutting face quick and then the bottom rake of that face lightly.

And as Prostheta said, keep them from getting hot, so watch your speeds and feeds. A lot of times cutting slower gets you done faster because the bit can clear chips easier and clogs less.

[Prostheta]

Bigger is not better unless you have the power in your drill press too....not that it's the direct topic of discussion here! I rarely use anything larger than 16mm in my drill press as I like the rate of progress I can maintain at that size.

These are sexy, and really shouldn't be in a section headed "boring tools":

http://www.axminster.co.uk/product.asp?pf_id=790505

WOOF.

[avengers63]

These are sexy, and really shouldn't be in a section headed "boring tools":

http://www.axminster.co.uk/product.asp?pf_id=790505

WOOF.

hehehehehehehehe

tool porn

[soapbarstrat]

Stay away from the damn Chinese forstner bits ( Harbor Freight, etc). I have a set. What I spent on them, would have been more useful even just paying the shipping for quality bits.

[Prostheta]

Totally. I don't buy Harbour Freight (being in the UK) but the same applies. Buy good bits and look after them. They should - by rights - see you through better than several cheap ass bits, and give you better results also.

[Woodenspoke]

I don't see where you can find many fostner bits that are not Chinese. Awhile back I learned that a set of fostner bits with teeth rather than a rim were faster cutting and needed less touch up work over time.

I use the original drill doctor. All of these home machines sharpen standard two flute drill bits at 118 Deg and 135 deg split point. Thats it. Except to note they also sharpen carbide and cobalt bits as well as HSS. Its convenient that I do not have to buy new bits when they are toast. Plus after inheriting several hundred dull ones it has paid for itself.

Edited October 22, 2008 by Woodenspoke