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Festool's Super Forstner Bit: The Zobo

By Rain Noe - November 26, 2013

in Hand Tools

I love Forstner bits as much as I hate spade bits. Is there anything as satisfying as boring that smooth-sided, flat-bottomed hinge-cup hole in a cabinet-door-to-be? If your application requires you to go all the way through your workpiece, sure, you can get some nasty tear-out; my solution is to use a backer board of wood a different color than your piece. That way, when you see differently-colored shavings start to come up, you know you've gone all the way through.

All Forstner bits are not created equal, of course. I own several makes: Irwin, Freud, and some crappy no-name Made in China and Made in Taiwan bits I bought at the local mom-and-pop hardware store (before I was thrown out and permanently banned after getting into an argument with the owner over a sink aerator. Ah, NYC). The Freud seems to do the best job of evacuating the chips, while the others require more corkscrewing/hula-hooping and/or mid-drilling vacuuming. I know Freud manufactures in Western Europe, and I suspect Irwin manufactures in China, perhaps explaining the quality discrepancy. And now I've caught wind of a kind of super Forstner bit, this one out of Germany.

Festool's Zobo bits look pretty awesome from a design standpoint. What they've done is created a hollow chamber in the center, in which you can insert your pilot bit of choice and even adjust its depth. This allows you to drill big-ass holes at crazy angles without a drill press and jig, or if you're in the field with nothing more than a hand drill. Using a pilot bit also allows you to drill the hole from both sides, tear-out free, if you can't be bothered with a backer board. Check 'em out:

I must admit this DIY hobbyist has no need for the Zobos, I'm just admiring the thinking that went into them. The tradesperson who needs to drill angled holes into 2×4 studs to run cable sheathing and the like would probably find them more useful. Indeed, Festool's target market is the traveling tradesman--and that's reflected in the price: $225 for a set of five, from 5/8” to 1-1/2”. (There's no 1-3/8” bit for hinge cups, so I suspect that the prevalence of pre-drilled cabinet doors are to blame.)

By the bye, if any of you have direct experience and recommendations for particular brands of bits, please do sound off in the comments. I'm always wary of my own anecdotal experiences, as I don't have enough representative samples; did I just get a bum Irwin bit? Do Ryobi bits break more often than other brands or is it just me? Help expand the knowledge base with your own experiences.

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rich

11 years ago

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If you look for a super forstner bit go for the Gold-Star by Schlagring from Germany. It is equipped with an exchangeable Carbide cutting surface. A bit expensive though. Starts at 193 Euros for the smallest one.... Or get a set of four for only 774 euros ;-)
Go to page 65. http://www.schlagring.com/schlagring-128.pdf
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name

11 years ago

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The professional way to drill a through hole with a forstner bit is to drill a very small pilot hole first and then go in with the forstner bit from both sides, only going half way through. The holes will match perfectly and you will have sharp edges on both sides.
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tmacd

11 years ago

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It looks like the pilot bit secures with a taper. Similar to the way a drill chuck mounts to a drill press spindle.
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Nathan G

11 years ago

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Firstly Festool design and manufacture terrific tools, which I have admired for sometime and had the opportunity to use on few occasions.

The most interesting thing for me from the post was looking at the way in which the Forstner Bit secures the pilot bit in the hollow chamber. I have absolutely no idea how it works but looks interesting if anyone has information on it.
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Brian Quan

11 years ago

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Fascinating rethink. I could see how the adjustable pilot has benefits. The most interesting part looks to be ease of sharpening.

As much as possible, my drilling takes place on a drill press or mill (for holes that matter). I've been quite satisfied with the performance of the Colt Forstners and pen drills. I'm less happy with the cost, but you do get what you pay for.
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bschelin

11 years ago

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I can certainly attest to the break-happy nature of Ryobi bits.
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