This is boring.

I have several excellent braces and a complete set of vintage Irwin pattern bits that a friend gave me, but I rarely use them for woodworking.  I use them regularly for carpentry because the bits work great in douglas-fir but the lead screws won't draw the bits into hard woods like oak.  I had been toying with purchasing some new Jennings pattern bits from Tools for Working Wood, though at $32-43 apiece they aren't cheap.  Then the other day we stopped at a garage sale.  I was walking back to the car when my wife said, "Did you see these?"  I hadn't:

Inside was a neat little three layered box:

and when I opened it, I found a complete set of Russell Jennings auger bits in great condition wrapped in tissue paper:

I paid $30. Online prices are all over, so I don't know whether this is a good deal or not, but I am pleased to have the set.

An interesting and puzzling, to me at least, sidenote is where the 32 1/2 comes from.  The bits are graduated from 1/4" to 1" by sixteenths and, if you add up the thirteen bits, the sum is 130/16.  Dividing the numerator and denominator by 4 yields (32 1/2)/4.  Odd.

I don't know a great deal about auger bits so I have been doing some research.  The bits I have are Model 100 RJ, which means they have a double-threaded lead screw and are meant for woods "not extremely gummy or hard" according to the label. The Russell Jennings company also made a 101 which, according to a label I found online, have a "single thread point for quick boring which is especially adapted for hard or gummy woods, end grain boring, mortising doors, etc."  The label indicates that the 100s are the ones used by cabinet makers and that the lead screw is the only difference between the two versions.  There are conflicting opinions about the relative merits of the two types and I cannot find a head to head test online.

I happen to have one auger bit made by the Russell Jennings Company some time before 1944 when Stanley acquired it and think it is interesting to look at the three varieties of size 15 (15/16") bits side by side:

You can see that the original Russell Jennings bit on the left and the Stanley version in the middle have many more twists on the shank than the Irwin bit on the right.  I have no idea which one will clear chips better but it does seem as if the Russell Jennings bits might be stronger.  Now, take a look at the lead screws close up:

The Irwin bit appears to be much coarser, but this is misleading because the Stanley Jennings pattern bit next to it has double threads.  Imagine two of your fingers tracing a spiral next to each other.  What this means is that the screw actually penetrates the workpiece at twice the rate as appears from looking at the threads.  Doing the best I could with my fingernail, I got 7 revolutions on the Irwin lead screw, 6 on the Russell Jennings bit and 5 1/2 on the Stanley.  I also tested this by boring holes in a piece of alder with similar results.  It took 15 revolutions to get through with the Irwin but only 13 1/2 and 13 with the Russell Jennings and Stanley bits respectively.  These results are consistent with others I have seen online.

The next test I conducted was to see if they would bore a hole in 5/4 dry white oak.  The Irwin and Russell Jennings bits did fine but the Stanley stalled.  Looking at it, it appeared that the threads on the snail clogged up.  I then used a trick that Bob Rozaieski shared.  I bored a hole in the alder just to the depth of the lead screw and covered the threads on the lead screw with green honing compound.  Then I threaded it into the hole and worked it back and forth several dozen times.  I re-attempted to bore a hole with the bit and it worked fine.  Clearly the snail needs to be clean and polished to do its job well.

So what's up?  It's not clear to me whether one design is superior to the other.  I cannot provide a technical explanation of the relative merits of double threaded and single threaded snails on auger bits.  The most important thing seems to be to make sure they are tuned-up very well.  Looking back, I think the problem I had with the Irwin pattern bits in hardwood was a result of maintenance not design.