Tool Talk

Woodworking Forum => Woodworking Forum => Topic started by: rusty on November 11, 2012, 01:14:35 PM

Title: Strange Bit
Post by: rusty on November 11, 2012, 01:14:35 PM
Strange little oddity I have never seen before. I would have called it a forsner bit, but it has no point.
Very small....and won't go very deep.
For inlay?

(Ed: It has a chisel edge inside, it doesn't show very well in the picture)
Title: Re: Strange Bit
Post by: Branson on November 12, 2012, 08:03:13 AM
Looks like you'd need to start a hole with one bit, and then use this one for depth.  It doesn't look like it is limited to the size of the working end.  Can't see it for inlay work.  Could be for chair making maybe.  When you're drilling mortices in the legs for the rungs, the lead screws on auger bits tend to
burst through the other side if you get the depth you want. 
Title: Re: Strange Bit
Post by: mrchuck on November 12, 2012, 10:04:54 AM
Maybe a "plug cutter"?
Title: Re: Strange Bit
Post by: rusty on November 12, 2012, 10:39:25 AM

It won't cut a plug, because the chisel edge inside will eat the plug. I was thinking of plugs when I looked at it because of the diameter, but it's useless as a top reaming tool as it has no point to guide it.
However I think Brandon's idea is probably correct, a hole bottom finishing tool , so you get a nice flat bottom on your hole. Saves risking going through the wood with the drill by trying to drill right down to the very last little bit of wood before breaking through...
Title: Re: Strange Bit
Post by: couchspring on November 12, 2012, 12:58:14 PM
forstner bit
Title: Re: Strange Bit
Post by: jimwrench on November 12, 2012, 04:31:26 PM
Agree its a Forstner bit. Patent Feb 23,1876 Mine has a very tiny nib that only protudes maybe 1/32 past bottom face of bit.
Title: Re: Strange Bit
Post by: Bill Houghton on November 17, 2012, 06:50:31 PM
It is an odd design; not sure how you'd get it started.  Maybe you need another bit to start the hole, followed by this to finish it.

I've found so many strange bits out there...designs that seemed genius to the person who developed them, but not by the market.
Title: Re: Strange Bit
Post by: mikeswrenches on December 01, 2012, 03:28:50 PM
I have a 5/8 and a 1 in.  The 5/8 has patent dates of 9-22-1874 and 2-23-1886 which corresponds to patent no's 155,148 and 336,709 respectively.  The 1in. Only has the 1886 date.

Both were issued to Benjamin Forstner.

Mike