Woodrat router bits that "snap"?!

[Dave McGeehan]

In the August 2007 issue of Woodwork magazine there is a very good article on how to build a hutch which incorporates a variety of curves. On page 63 the author explains how he cuts very narrow pin openings between his tails using a special router bit made by Woodrat. But what really stunned me was this: "These bits are somewhat delicate, and eventually snap, but I can get several sets of drawers from one $15 bit." I have always been under the impression that a "snapped" router bit has the potential to be devastating and never worth the risk no matter what the advantage. A friend of mine also saw the article and said he was shocked by the nonchalant manner it was mentioned. Am I misunderstanding something here? I'd love to try a bit that could cut narrow pin openings but not if there is ever a chance of them "snapping."

Dave

[Doug Shepard]

I dont know if I'd be shocked, but surprised anyway that they tend to break that easily. I've done quite a bit of 1/16" inlay though and I pretty much expect to lose one of those once in a while so maybe I've just gotten more used to the idea.

[pat warner]

Not only is that cutter fragile but almost all dovetail bits suffer from the same fragility.
Moreover, there are many seemingly ordinary cutters that are quite flexible and subject to breaking.

A rough standard for a cutter in the danger zone:
Cutting length (flute length) 4x the shank diameter max., and that spec is quite conditional depending on the cutter design (single flute, profile, radial or axial config. & so on).
Buyer beware, & at the very least, it is respectable to disclose fragility or any other parameter to keep you in the safety zone.

One note of consolation: Almost always, the dovetail bit is in its own pathway. As such, if it breaks it can't jump the tracks; it's stuck there & you won't get hurt.

Routers (http://www.patwarner.com)

[Steve Clardy]

I've broke several larger bits over the years, usually straight bits.
They have always stopped in the workpiece. Never flew out and hit anything.

[Gary Curtis]

A key fact about WoodRat is that they sell only HSS steel bits. No carbide. If you would see their 4.7mm (a little more than 1/8th") dovetail bit, with its 1:9 profile, you'd understand the logic. These dovetails are elegant. Not possible with carbide because of the brazing of the cutter to the shaft.

HSS also can be honed to a sharper edge because of the grain structure of the metal.

In straight bits from WoodRat it gets more exteme. They sell 1.6mm, a 3mm, a 4mm and a 5. All to achieve an elegant look with joinery like Box Joints.

Because they are so thin, they are relatively fragile. We just go slow, and I have yet to break one.

Gary Curtis:o

[Jim Nardi]

Never had them do anything but fall straight down or stick in the piece of work. Had a couple fall out now that's scary.

[Dave McGeehan]

Thanks for the responses. After 20 years as a serious hobbiest and more recently as a professional, I've never had a router bit break. I've always assumed, via theory and one particularly bad injury to a friend, that a snapped bit had a better than 50% chance of traveling far enough to be dangerous. Although your responses tell me that's the exception, I still hope I my luck (and all of ours) continues.

Dave

[Jim Becker]

One other thing with cutting dovetails and other "captive" profiles...don't shove them into the wood with wild abandon! Let them cut their way in with just a gentle push from you. This reduces stress to the fragile narrow neck of these cutters.

[John Lucas]

I can vouch for the tiny little DT bts by WoodRat. When I first saw them I knew why they sold them in sets of three. I just knew they would be breaking. BUT, I took everything slow and they worked just fine.

http://www.woodshopdemos.com/wr-5.h7.jpg

But, little DT bits can make little boxes:
http://www.woodshopdemos.com/wr-5.h2.jpg