Auger bit types

[Mark Stutz]

Dennis McDonough recently started a thread about hand drills, but I didn't want to hijack it.:D Bob Smalser made mention of the various auger bits. I had no idea that Irwin were made for soft wood and the Jennings for hard wood. Other than the name stamped on the bit, is there a ready way to tell them apart, since I have to get out the magnifying glass to read the names. It may be obvious, but after looking at several of mine--Irwin, Jennings, Swan, "no name"--I can't seem to identify a difference other than the obvious--single v. double twist etc.

Thanks. Mark

[Kevin French]

http://www.fine-tools.com/bohr2.htm

[Joe Rogers]

I have always heard that the pitch of the lead screw is the determining factor that relates to wood type use. Fine threads = hardwood. Medium pitch is for softer hardwoods. Coarse pitch lead screw threads for softwoods. I have sets of the fine and coarse auger bits. Haven't found meduim thread bits yet. In use the thread pitch determines the rate the tool feeds into the wood and of course the faster coarse pitch works in soft woods. In hardwood the coarse pitch will strip out and the bit stops cutting DAMHIKT :DJR

[Mark Stutz]

Thanks. I didn't think to look at the lead screw.:o

[Bob Smalser]

Don't overlook barefoot augers for long holes. Lack of a lead screw allowed them to drill deep without following the wood grain. Used with a "preacher" or long jig to keep them aligned.

They're both expensive and hard to find, however, and I kinda enjoy needling my boatbuilding purist friends by teaching builders how to drill long and straight with common electrician's bits available at Home Despot and dowel jigs:

http://pic3.picturetrail.com/VOL12/1104763/6583947/84760753.jpg

[Harry Goodwin]

Bob: This is the first picture of my doweling jig ,I cherrish. In my poorer days financially I used it for everything biscuits and Kreg do for me now. Stanley made a keeper that time. Harry

[John Dougherty]

I've heard - salt, grain - that augers for soft woods have a coarser threaded lead screw that breaks of the wood fiber less. Hard woods conversely have finer threads, but I can't say that I have ever used bits with a noticeable difference.

[Jim Koepke]

Wow, the resurrection of a fifteen year old thread. This is from before my even finding SMC. Amazing how much knowledge has seeped into my brain from these old pages.


Other than the name stamped on the bit, is there a ready way to tell them apart

Mark, glad to see you are still a contributor. You asked about telling the bits apart. Irwin pattern bits are single twist and Russell Jennings pattern are double twist. For the faster or slower bits it is in the lead screw:

452866

Note the double thread lead screw, on the right, pulls in two threads for each turn.

In the group on the left the center bit is a Russell Jennings pattern. In the group on the right the bit on the right is an Irwin pattern. These bits may have been made by different makers than Irwin or Russell Jennings.

There is also A Bit About Augers > https://sawmillcreek.org/showthread.php?131238

jtk

[Mark Stutz]

Thanks, Jim. I was away for several years as life got in the way, but am now retired and gradually getting back into the swing (no pun intended)of things. I rea;;y appreciate all of your input. I read much more than I post!