A Bit About Augers...

[Jim Koepke]

One of the common boring tools is the auger. Though they may look a lot alike on first glance, there are a lot of differences involved. After all, there were a lot of different trades that needed to put holes in wood. Very often, there were different needs among the different trades. Cabinet makers would want a clean hole of a precise size. A carpenter might not care about the size as much as being able to make a hole quickly in a cramped place. Another trade might want to be able to bore into wet wood and so on. The particular trades that the bits were made for decades ago is likely long separated from the twisted and tarnished pieces of steel we find today at yard sales, flea markets and through auctions on line.

Lead Screw & Caliper.jpg

Here is a group of #8 auger bits. They are numbered in 1/16 inch increments. Most standard sets start at 4 and run through 16. Larger bits are common. Smaller bits are scarce. In the picture wire has been wrapped around the lead screw to show the single and double threading of the lead screws.

Notice also some of the spirals are double helix and some are single. The single helixes do not clog with waste removal, the double helix will track truer in a hole.

Here is a close up of the single and double lead screws.

Single & Double.jpg


With larger bits, it is often a good idea to drill a small pilot hole to prevent splitting the piece being bored. In this case, a #18 bit is being used in pine. The hole is started and when the lead screw breaks through the far side, the bit is backed out and the hole is finished from the far side.

First Cut.jpg

Notice the shavings coming off the bit. They should be even from each side of the bit. These are a little thick due to the bit being dull. If shavings are coming off only one lip, it means it is cutting first. Some metal will have to be removed from it to get the other lip to touch at the same time. If the two lips are performing equally, then when sharpening, make sure to remove the same amount of material from each.

An auger file is also known as a safety file. Two of the opposing surfaces will cut and the edges are smooth. When sharpening the lip edge on the bit, only file on the top side and be careful not to damage the lead screw.

The Lip.jpg

When sharpening the spurs, only file on the inside. Remove as little material as possible from the leading edge and the area that touches the wood first when boring. Removing metal from the outside will alter the diameter when starting a hole and the rest of the bit will bind in the under sized hole.

The Spurs.jpg

After the bit has been sharpened, the shavings will look a little thiner and cutting will be easier.

Sharp Cut.jpg

If one bores through a piece without stopping to finish from the far side, then the hole will "blow out" when the bit exits the wood. The first hole is a bit rough from the dullness of the bit. The second hole is sharp, but the "blow out" from the third hole did extend to the second hole.

1st, 2nd & Blowout.jpg

As far as all the different styles of auger bit, my knowledge is limited. Some work slower and do not eject the waste as fast. The ones with more aggressive lead screws will go through the wood faster and need to have more space between the spirals to move the shavings.

Hope this helps in the understanding of making holes.

jim

[Bob Glenn]

Wow. Thanks Jim for the investigation and this post. I love using augers to bore holes, but never gave them a second thought. I heard, but never measured that some augers will drill over size.

[Jim Koepke]

I think it was getting late and I forgot to mention that the lead screw determines how aggressively the bit goes through the wood. Then that the double lead screw types will often be more aggressive because the spacing is actually two threads for each turn. The extra threading helps to keep them from pulling out.

In hard woods, a finer thread pitch will be less likely to strip out and a faster bit, coarser lead screw pitch, can be used in soft woods.

jim

[David Gilbert]

Jim, thanks for the tutorial. I have a much better appreciation of my purchase the other day and am looking forward to using them.

It's interesting how the companies that made these auger bits must have really understood how and why these worked. I'm wondering if this "technology" has been largely lost by our tool producers. I understand what a game changer the power drill was (corded and then with a battery) and certainly spade bits are a lot cheaper to make than these elegant auger bits. I'm surprised that these don't have a more prominent place in our shops.

Wonderful information!

Thanks again,
David

[Randy Bonella]

Jim,
Thanks for the tutorial! very timely for me as I'm now inching closer to needing some of these.

Greatly appreciate the info!!!

Randy...

[harry strasil]

Very well presented and explained Jim. Now for a little History Lesson. One minor detail you left out tho, one end of the Auger File is Safe on the Flats and the other end is Safe on the Edges.

Spade bits are an evolution of the old Centre Drill. 5 thru 10 in the photo, from the Left side.



And twist drills are an evolution of the Gimlet.

FWIW, Way back when, a Blacksmith, Name forgotten thru time, Invented what we know as the Auger Bit. But, he had a preference for spirits and at the time the Apothecary, We know it today as a Drug Store, was the place to get them other than a Saloon.

Said Blacksmith ran up quite a bill at the next door apothecary, and having patented his Auger Bit, he traded his Patent to the Druggist whose name was Russell Jennings to pay his bar bill.

Mr. Jennings seeing the value of the Invention and being well fixed but not filthy rich, he set up a Factory to mass produce the Invention that he acquired from the Old Blacksmith.

Then Mr. Jennings became a filthy rich Druggist and Manufacturer.

[Jim Koepke]

Thanks Harry,

Leave it to someone who was probably invited to the meeting to decide what they were going to call dirt to know these interesting bits of history.

jim

[harry strasil]

I read a lot, there are lots of interesting bits of Tool History and the people who made them in "The Antique TOOL COLLECTORS Guide to Value" by Ronald S. Barlow, ISBN 0-933846-01-0

[harry strasil]

I guess my hard drive (brain) is more than at capacity, with all the Blacksmithing, Machining and Woodworking Information stored therein, I don't have trouble remembering, its the retreval (Search Function) that is hampered by the capacity problem, then there is the file on Historical things, file on daily duties, and other such trivia, that are always fighting for space.

[Rick Erickson]

Reviving an old(er) thread. Does anyone know if the older bits are of a better quality than the new ones? I can buy a set of 6 Irwin bits (old or new) for about the same price. The design of the new ones is a bit different.

[Jim Koepke]

Reviving an old(er) thread. Does anyone know if the older bits are of a better quality than the new ones? I can buy a set of 6 Irwin bits (old or new) for about the same price. The design of the new ones is a bit different.

What are the design changes?

I have a lot of Irwin bits. They are fairly decent. I have some older Russell Jennings that I like a lot better. The older Russell Jennings have double twist all the way up that seem to help them track a hole a little better than the single flute on the Irwin.

There are also a lot of things to consider between different styles of bits by the same maker. Some are made for faster boring and some are made to cut slower. Faster is usually designed for people installing plumbing or wiring. Slower is for cabinet work and finish work.

jim

[Ross Canant]

Fine thread lead screws for dry hardwood. Coarse lead screws for softwoods and green wood.

[Rick Erickson]

What are the design changes?
jim

When I say design changes - all that means is they look different to me. I'm just getting into braces and am looking for a good set of bits. Should I just buy the new ones bit by bit as needed or buy a older set that looks complete. In general are the older ones (found on the antique sites) sharp and in good condition or are they abused (I would never know).

[Bob Easton]

Hey Rick, If you go for new augers, look for those with a double helix. As Jim mentioned, they stay truer in the hole. Now, since I haven't paid more than a passing glance at the new bits in the store, I have no idea if double helix types are available. ... or if new ones are available with square shanks that fit my braces.

I DO see a lot of sets of older Russell Jennings bits for sale on eBay. They appear at the rate of 4 or 5 sets a week. About 80% of those listings are full sets, 4 through 16. The others often have one bit missing or a substitution here and there. Many are in quite good condition, and about once a month someone offers a boxed set with the bits still in the original paper wrappers. The three-tier boxed sets go for $80 - $150 depending on condition .... and if you compare that with new bits, I think you'll find the prices on par.

I know this because I set up a search, the kind that runs daily and sends an email when it finds something. I watched the auctions for about a month to get a sense of the offers, conditions, and typical sale prices. Then, I waited for the right set to come along. I bought one in a canvas roll rather than the wooden box, won for about $40 less than the boxed sets, and am very pleased with it. An overnight soak in plain ole vinegar and the bits are clean. They were all sharp. The smallest had a bit of a bow in it but was easily coaxed back to straight in a vise.

My eBay experiences lead me to believe that the sellers with a return policy are a lot more accurate in their descriptions, and they often include sharpness as part of the initial description so they don't have to spend time answering questions. I also tend to look at the seller's other merchandise. If the seller isn't selling a lot of tools, but some other yard-sale specials, I run away and look elsewhere. So far, buying from people who have return policies and buying from people who deal with a lot of tools has worked OK.

[Eric Brown]

I would like to see a discussion about some of the different auger designs too. I found this on google books:

http://books.google.com/books?id=8dw...%20bit&f=false

The Ford and ship augers sound interesting. I wonder how you start a bit with no center screw? Perhaps you use another board with a hole as a guide?

It would also be nice to see a better brace comparison. Seems to me that The spofford style having no ratchet mechanism might have a good balance and less "wobble" for smaller, precise holes, while the ball-bearing ones being heavier may help with deeper holes. Do the old "Ultimatum" type braces use a special bit? Is the brace swing to use determined by the bit size, the woodworkers strength, the speed, and are shorter swings able to make truer holes easier than long swings? Do ball bearing heads only matter if you need to ratchet, or do they also reduce "wobble". Are dowel bits not just shorter than regular, but slightly undersized too? Many questions.

Hey Jim, would you be interested in doing a study for us?

Thanks. Eric