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View Full Version : forstner bits feed pressure versus spade. which is easier?



Cory filder
02-27-2023, 1:26 PM
I don't own any forstner bits yet. I a, considering getting one for a project. I understand that the holes are more accurate and nicer. But the only question I have for the moment is feed pressure. I understand they are slower than spate bits, but what I want to know is even though it goes slower than a spade, is less the pressure required? This is an unusual requirement, but for strange reason I will not get into it is one that is needed now ( whichever requires less pressure)
Thanks

Lee Schierer
02-27-2023, 1:42 PM
If you don't have a drill press, using a Forstner bit in a hand drill is very tricky without doing damage to the work piece.

Some spade bits are self feeding so no real pressure is needed. Pressure needed for Forstner bits increases with the diameter of the hole. Forstner bits do make nice clean almost flat bottom holes. However, if you drill a through hole with them you can get a lot of tear out on the back side unless you stop just short of breakthrough and flip the work piece to drill from the other side.

Michael Burnside
02-27-2023, 2:14 PM
Spade bits are more for construction type applications. Anything woodworking should use a Forstner bit IMHO. If you're drilling a hole less than 1" then they aren't too difficult to use with a drill, but anything larger and I prefer a drill press. Even a cheap drill press can handle a good bit of reasonable size.

Best advice I can give for using them is use a lower RPM on hardwoods and a little higher on soft and let the bit do the cutting. If you're pushing really hard, time for a new bit or sharpening.

Cory filder
02-27-2023, 2:54 PM
I am using a drill press. I'm only considering that application. my drill press belts are too difficult to change.Wish I knew that when I bought it. I keep it at 900 rpm, a little slow for woodworking (IMHO)but A little fast For metal for larger bits.

Richard Coers
02-27-2023, 3:11 PM
Depends on the quality of both bits. You can buy flat spade bits and you can buy spade bits with spurs out on the edges. You can buy cheap forstner bits that barely cut, and you can buy carbide tipped with incredibly sharp carbide spurs. Like always you get what you pay for and feed pressure is all over the spectrum. Cheap forstner bits can build up tremendous heat and you can discolor them and get smoke after one hole, but it's a clean hole. Cheap spade bits rattle around when you drill and it's very easy to get a hole that is not round. Your choice.

glenn bradley
02-27-2023, 3:12 PM
I am using a drill press. I'm only considering that application. my drill press belts are too difficult to change.Wish I knew that when I bought it. I keep it at 900 rpm, a little slow for woodworking (IMHO)but A little fast For metal for larger bits.

Does the motor or some pulley not unlock for belt changes? What DP is it? My previous DP had enough room in the head casting for link belts which made changes a lot easier. My current DP could take them in 3/8" but I only have 1/2" and the mechanism on the new DP makes changes with typical belts OK. Proper speed for a given bit makes a dramatic difference in the performance of the cutter. I would try to resolve your belt change difficulty.

All that unrequested advice having been already given :D . . . I rarely use a spade in a drill press since even at its best the cut result is poor. If you need the DP for accuracy / repeatability, the spade will cut softer wood pretty quick but a sharp Forstner is pretty darn fast in hard or soft wood.

Edward Weber
02-27-2023, 3:16 PM
Forstener bits should not require any great amount of pressure, it they do, something is wrong.

A drill press is named because of it's similarity in appearance to a manual arbor press, NOT because you use it as a press. Other parts of the world it's a Pillar drill.
Those who apply too much pressure by hanging on the spokes are not doing themselves any good. All they end up doing is burning hole and slipping belts.

A lot depends on the size of the bit and the wood being bored.

Cory filder
02-27-2023, 3:40 PM
It's a Canadian tire drill press. Consider quality similar to ryobi. I change the belts a few months ago with a friend and we were struggling. Two people. we even read the instructions! Resolving the belt issue requires Selling it on Craigslist. it's that bad. I'm stuck with that at the moment. that's a good idea about the link belts. Never been a fan of them, but It might be good In this application.

Cory filder
02-27-2023, 3:43 PM
the forstner it considering is a HSS speced by lee Valley tools. It's a knife edge type, but the knife is small.

it's hard in my arms at the moment to give high fee pressure. I mostly work in softwoods

I am still not exactly clear if decent quality forstner is easier than a spade.I guess if I use one I wouldunderstand. I would buy to try but they are a bit expensive

Mike Cutler
02-27-2023, 3:48 PM
Cory
I have never used a spade bit in hardwoods. Only softwoods.
I don’t really think there would be much pressure difference between the two, if they drill the same diameter hole.
900rpm is pretty fast for a Forstner bit. My slowest drill speed is 525 rpm and that’s too fast for a Forstner bit any larger than an 3/4”.

Tom M King
02-27-2023, 3:48 PM
Get one of these and you will not have much feed pressure required. They call them Forstner bits, but they're really Multi-Spur bits, but cut as clean a hole as a Forstner bit.
https://www.infinitytools.com/famag-bormax-2-0-forstner-bits

For less money, one of the wavy edged Freuds don't require much pressure either.

Rick Potter
02-27-2023, 3:55 PM
Hi Cory,

You probably know this tip already, but since you are new, I will repeat it.

You can get very clean holes with a spade bit by drilling one side until the point comes out the bottom a bit, set your DP depth to that point, then turn the work over an use the small hole to guide you while drilling from the bottom side. If you are using a fence, be sure to flip it so the same side is against it. Bingo, clean entry and exit.

Walter Mooney
02-27-2023, 4:41 PM
Cory,
One thing that I don’t think has been asked yet is will your holes be through holes or ‘stopped’ holes? IMO, if they’ll be stopped holes then Forstner bits are what’s needed, because spade bits IME have a much longer point and this might poke or break through the ‘other’ side of your work. And the tip on a Forstner is much shorter, so probably won’t poke through the other side of the work.
Good luck, hope it all works out for you.

Cory filder
02-27-2023, 5:33 PM
these are really great tips. One thing you taught me for sure is the only way to know (How it feels) for sure is to try it myself. they will be useful anyway
thank you everybody for your input
-Cory

John K Jordan
02-27-2023, 7:26 PM
I use forstners in both soft and quite hard woods including exotics. I use enough pressure to keep them cutting well.

If I want real clean holes I use good HSS bits. If that’s not important, such as for drilling long holes for things like pepper mills or in preparation for deep hollowing on the lathe I prefer to use carbide forstner bits.

One thing I discovered years ago and ALWAYS do now for deep holes is direct a strong stream of compressed air into the back of the hole behind the bit while drilling. This keeps the chips cleared (saves having to stop and back out the bit) and the bit cooler.

JKJ

roger wiegand
02-27-2023, 8:12 PM
For the lowest feed effort the Irwin Speedbor Max drills are hard to beat, or even faster, the Klein flex bit augur that electricians use for running wire through studs. The hole quality is lousy, but the Klein bit will pull itself through almost anything with no effort on your part, other than hanging on to the drill for dear life (I find the bigger ones intimidatingly dangerous). I don't think they're appropriate for use in a drill press, and I wouldn't use them on a woodworking project, but they meet the criteria of low pressure.

My Fisch and Famax forstners require considerably less pressure than my el cheapo bits, FWIW.

John K Jordan
02-27-2023, 10:06 PM
… Irwin Speedbor Max …

I use those for almost all wiring. The screw threads pull the bit in, the three points cut incredibly fast. I also like the hex shaft that locks quickly into chucks on all the impact drivers. Sure does leave a nasty hole but does it effortlessly, especially nice when working overhead.
https://www.amazon.com/IRWIN-Tools-SPEEDBOR-3-Piece-3041003/dp/B000LQ9054

Andrew More
02-27-2023, 11:18 PM
One thing I discovered years ago and ALWAYS do now for deep holes is direct a strong stream of compressed air into the back of the hole behind the bit while drilling. This keeps the chips cleared (saves having to stop and back out the bit) and the bit cooler.

How do you direct the air down into the hole? Is there a simple solution to this? I'm aware of compressor blow guns, but they'd need to have the trigger fixed on, and attached to the drill in some manner.

Keith Christopher
02-28-2023, 2:50 AM
I recently purchased some nice Freud forstner bits <not a sponsor> they cut super nice, I also bought the rockler <also not a sponsor> 'drill press' attachment for a hand drill. and let me tell you money well spent !