# Forstner bits in hand drills?



## Beowolf (22 Mar 2010)

I've not come across forstner bits until recently. It's my understanding they drill much cleaner holes than a spade bit would. 

Also, everything I've read hints - but doesn't explicitly state - that you can't really use them in a hand drill. Is that correct?

Is it the case that if I attempted this in oak, I would still be standing there this time next week?


----------



## miles_hot (22 Mar 2010)

I use them a hand held dewalt drill with no real issues however I suspect I woudl get a more precise hole with a pillar drill....


----------



## Henning (22 Mar 2010)

Well, in my extreme newbieness i've used several different sizes of Forstner bits in hand drills and that has worked quite ok. 
I've never seen anywhere which says you can't?


----------



## RogerS (22 Mar 2010)

I think he means one of these maybe ?


----------



## Dibs-h (22 Mar 2010)

Beowolf":3hjttk9j said:


> ... hand drill.....
> 
> Is it the case that if I attempted this in oak, I would still be standing there this time next week?



I'd say yes - you'd be there a long time.


----------



## AndyT (22 Mar 2010)

Fostner bits are quite an old design - so you can sometimes find old ones made with a taper square shank to use in a hand brace. The extra level of control from drilling by hand means you don't have to use a drill press, which is essential if they are spinning fast.


----------



## matthewwh (22 Mar 2010)

Traditional cylinder bodied Forstners can generally be used in a hand held power drill as long as you are competent at drilling absolutely dead square and perpendicular to the surface or you use a drill guide. The problem with these is that they are prone to overheating, painstakingly slow and the slightest loss of concentricity in the hole leads to more friction which accelerates wear causing blunt edges, more overheating.....etc.

TCT forstners with protruding teeth are liable to screw up your work properly if you get them slightly off angle or try to drill intersecting holes. The cutting edges are unguided so they can dig in, bounce out of the hole and go for a stroll across your surface...wheeeeeee, dug, dug, dug, dug, dug...oh bu££er!

Saw tooth forstners were the next development and the interrupted edge isolates the friction into spots so there is less chance for the heat to build up. Famag went one stage further with their Bormax range and developed a bit specifically for use in both pillar and hand held drills. They interrupted not only the cutting edge but also the sidewalls of the cylinder, so there is much less heat build up. This is effective to the extent that you can use the bit for a couple of minutes and within ten or fifteen seconds clench it in the palm of your hand. They do a version of the standard carbon steel ones with a replacable centre so you can fit a normal tip, a longer pilot drill for entering timber at an angle or solid bore followers for counterboring existing holes.

The latest development are the Bormax 3 carbide tipped forstners which are similar in design but have carbide cutters and integral (therefore guided so no bounce-out) carbide spurs on the edge. These cut really fast - like three times the speed of the carbon steel version and will take on really nasty materials too. They don't need sharpening anywhere near as often as carbon steel ones - maybe every one or two years if you are using them regularly.


----------



## paininthe (22 Mar 2010)

I bought this set, more for a play than anything else.

http://www.screwfix.com/prods/92393...ner-Bits/Erbauer-Forstner-Drill-Bit-Set-5Pcs#

I have used the 25mm into Melamine faced MDF with a hand held power drill. They make a lovely clean hole in the melamine and swarf up the MDF lovely.

Unfortunately only for about 6 holes before the bit started slipping about on the melamine. They have been blunted as quick as that.

I now have quite a lot of holes to do so looking at Matthews post above i'm looking at something of greater quality.

Because it is melamine and a very high quality melamine at that, I could do with recommendations.


----------



## jimi43 (22 Mar 2010)

I bought a set of the cheaper Chinese Forstner bits way back in the dark days...and they blunted so quickly they are worthless really.

I picked up some Bosch ones at a bootfair...guy was selling them every week and I just picked up the odd size one at a time each week for a quid.

The collection grew and now I have a drawer of them of all sizes and they are used a lot and are still sharp. They are plain carbon steel ones so I must try some of the ones Matt mentions....just for "good" jobs on the guitars.

Jim


----------



## Ironballs (22 Mar 2010)

Must try some of those newer ones Matthew, I have some of the cheapo gold ones from Axminster and I reckon they've probably blunted already without too much use.

In fact I tried using one to go through some 23mm sycamore and it was burning like twittery, ended up making a router template and doing it that way.

Back to the OP, I've only ever used Forstners in a drill press and wouldn't want to use one in a hand held


----------



## big soft moose (22 Mar 2010)

we use the cheapo axminster set in the 24v sds (fitted with a 13mm adaptor chuck) all the time - the only issue is keeping it square and we use one oner those drilling guides from screwfix for that.

main use is removing bulk waste when cutting sign mortices in the feild - ie when adding a mortice to a sign post allready set in the ground

they do blunt quite quick particulary in ecodeck but you can tickle them back up with a file - and as they are cheap it isnt the end of the world to have to scrap them and buy another one from time to time.


----------



## Keenedge (23 Mar 2010)

I've tried cheapo forstner bits and they get so hot in no time at all and then clog and spin and get even hotter. My Famag Bormax ones have been brilliant but I think I'm going to want to get the TCT versions. A mate of mine saw a demo of one and was very impressed especially on hard stuff like corian and hard, hard woods, a cool clean finish time after time.
I need to drill at angles every now and again and the guided version will save me bags of time in setting up.


----------



## Beowolf (23 Mar 2010)

Thanks for all the replies.

*Henning*: It wasn't so much anyone saying you can't, just that all the references seemed to mention pillar drills.

*RogerS*: I may be limited in my equipment, but not that limited! 

*AndyT*: Others say they use them in a hand held power drill - are they using drills with variable speed then? I'm not sure mine does that...

*matthewwh*: Drill guide it is then. 'Competent' and 'dead square' don't quite go together for me just yet.

I'll get one and give it a go. Just knowing it's possible is halfway there.


----------



## Henning (23 Mar 2010)

I have to admit to having a drill stand, though. (In addition to a pillar drill)

I found i get much better holes with the drill stand (Even though it's only a cheap wolfcraft) with any type of drill bits and the smaller ones doesn't brake due to me having them at an angle.
I am fortunate enough to have a really nice drill though. 

I have used my cheap forstner bits in a lot of different drills and it works just fine so just go for it.


----------



## aesmith (25 Mar 2010)

Never had a problem with Forstner bits either in a real hand drill, or a hand-held power drill. As a matter of fact I've never had any burning when using them under power, I guess I must drill a whole lot slower than you guys! Only problem I have is clogging. They don't clear chips very well and need to be drawn clear now and again.


----------



## loz (25 Mar 2010)

Yes,

And i even stand on the bowl blank i'm drilling into to stop it spinning round.........


----------



## jimi43 (25 Mar 2010)

Actually you have hit the nail on the head there aesmith.

Slow speed is important...this is not a twist drill. It must be allowed to cut and clear.

I just drilled some 22mm holes in some greenish chestnut which was round stock for some garden tools I am making for me old Mum....






I used the standard steel Bosch ones I was talking about and took my time to study the cutting action. What I found was that the slowest speed on my pillar drill worked best, no burning but some clogging as you suggest.

I pulled back the drill every few seconds to clear the cuttings and I found it did not clog at all. The breakout was a hell of a lot cleaner by doing this regularly too.

So I suppose it is thw way you use them.

The other thing I did was try them with a brace and with a DeWalt handheld battery drill. Clearly the pillar drill was best for accuracy of vertical but apart from that, clearing the swarf as I went, they both cut perfectly well.

Hope this test helps.

Jim


----------



## BradNaylor (26 Mar 2010)

RogerS":3cvdzxqm said:


> I think he means one of these maybe ?



I must be nearly as old as Roger.

To me a 'hand drill' is one of those things - not a hand-held power drill!

I've not used one since about 1978, mind!


----------

