Forstner bit for end grain?

[Elfinsafety]

Hi; I need a decent, capable forstner bit for end grain of hardwood. I was using a Bosch 40mm, but I think it's now beyond any further re-sharpening. I bought an Axcaliber one, but it's practically useless in end grain. I appreciate that trying to bore holes in end grain will wear bits out much quicker, but I need to be able to do that.

Are there any bits available that will allow me to do this and be more reliable? Looking at a Colt MaxiCut bit; are they really as good as claimed? Any alternatives?

Thanks.

 

[chipmunk]

I find that sawtooth bits rather than forstners are better for end-grain - especially in those bigger sizes.

I'm surprised that your Bosch bit is beyond sharpening. Have you been sharpening it correctly? Just down the front of the leading face of each cutting edge and on inside of any spurs is all it should take.

Jon

 

[Elfinsafety]

Well, I have been sharpening the cutting edges, and the round outer edges, but they are now 'higher' than the cutting edges, so they dig into the wod first, making the cutting more difficult, and leaving a 'trough' round the perimeter of the hole bottom. I'll need to grind those edges down; I've had a go but it appears to be a bit of task, and I'm not sure I'll be able to get both edges absolutely level. For the amount of time involved, a new bit is far more cost effective.

Point taken about sawtooth bits, but aren't they a bit 'rougher'? I need very smooth sides.

 

[paulm]

The sawtooth forstners are designed for end grain work I believe, certainly what I always used when drilling into end grain on the lathe, finish seemed fine for my purposes, not noticably different but it wasn't important for my work so I may just not have noticed.

Cheers, Paul

 

[chipmunk]

I only ever use a diamond hone and fine files on my forstners and sawtooth bits - At that rate I'd expect it to take a lot of resharpenings to end up with spurs behind the cutting edges but if that's the case then you're probably right about it being beyond salvage.

Sawtooth bits have teeth it's true but they are bevelled towards the inside to cut cleanly. Added to that, when drilling directly into end-grain, tear-out is really not all that likely IMHO because the wood fibres are in-line with the hole and so more or less unable to influence their neighbours beyond the edge of the hole. In fact I'd expect even a spade-bit with sharp spurs to cut pretty cleanly on true end-grain.

HTH
Jon