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.

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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.

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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.

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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.

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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.

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

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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.

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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.

http://img.photobucket.com/albums/v81/irnsrgn/wood/basicbracetools.jpg

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=8dwOAAAAYAAJ&pg=PA688&lpg=PA688&dq=ford+auger+bit&source=bl&ots=dxX_YKnO2e&sig=_Qq8GXrrazIstFD0QHIR2zO_tA8&hl=en&ei=KyOJS6r3FYbflAeEx6XQAQ&sa=X&oi=book_result&ct=result&resnum=9&ved=0CCMQ6AEwCA#v=onepage&q=ford%20auger%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

[Jim Koepke]

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

[snip]

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

Eric,

I am afraid my knowledge is only enough to make me look the fool if I tried to post a full study. What has been posted by me so far is about all I know on the subject.

Though I am always interested in learning more.

jim

[Steve Branam]

Any tricks to sharpening the lead screw? I have several sets of flea market auger bits in decent shape, but I've also picked up several large hand augers (1 1/2" to 2") with wooden T-handles that are not in such good shape. They usually look like they were buried in the back yard for 100 years.

Mostly they clean up well and can be resharpened, but the lead screws are encrusted and won't bite. With some difficulty I've been able to very carefully file the screw threads to some degree of sharpness, in a reasonably consistent spiral, to get them working. But I'm wondering if there's a better and more reliable way.

Then the other issue with them is that they don't have spurs, they're the pattern where the edge turns up. So once the screw clears the back side and has no more wood to bite into and pull the bit along, the cutting edge spins free. Where spurs would cut through that last little bit of wood, these bits start spiraling through the opening without cutting it. I could see where putting a backing board underneath would give the lead screw something to bite into, but how did they use these to bore into barrels?

[Jim Koepke]

Any tricks to sharpening the lead screw? I have several sets of flea market auger bits in decent shape, but I've also picked up several large hand augers (1 1/2" to 2") with wooden T-handles that are not in such good shape. They usually look like they were buried in the back yard for 100 years.

Mostly they clean up well and can be resharpened, but the lead screws are encrusted and won't bite. With some difficulty I've been able to very carefully file the screw threads to some degree of sharpness, in a reasonably consistent spiral, to get them working. But I'm wondering if there's a better and more reliable way.

Then the other issue with them is that they don't have spurs, they're the pattern where the edge turns up. So once the screw clears the back side and has no more wood to bite into and pull the bit along, the cutting edge spins free. Where spurs would cut through that last little bit of wood, these bits start spiraling through the opening without cutting it. I could see where putting a backing board underneath would give the lead screw something to bite into, but how did they use these to bore into barrels?

Hopefully Harry will chime in here and explain the usage of those bits. I think He talked about them before in another thread.

I have cleaned the lead screw by using a sharp awl point and metal bristle brushes. I have not had any that needed new threads cut. Most of mine are common enough that if that were the case I have another one to use.

One time tested method of preventing spin out and blow out is to stop drilling as soon as the lead screw breaks the surface on the opposite side and then drill from the far side.

I think barrel bung boring was done with a different kind of bit. That is another question someone else may be able to answer better.

jim

[Jim Koepke]

In recent weeks and confirmed during my current saw table project some new knowledge or understanding of auger bits came my way.

If one or both of the spurs are too short, you will get the effect seen in this picture.

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If one of the spurs is not below the cutting lip enough to scribe a semi circle before the lip starts to cut wood, a shaving may be left at the edge. Usually this can be shaved away with a chisel, but it is an annoyance.

So be careful when sharpening those spurs.

This hole was cut on an angled surface with the bit held plumb. In that case, it would be possible to hold the brace and bit perpendicular to the surface to scribe the circle and then back out the bit and restart with the brace and bit held plumb.

A bit with an aggressive pitch lead screw will need longer spurs than one with a fine pitch lead screw.

Just one more thing to think about.

jim

[Joel Goodman]

Any tricks to sharpening the lead screw?
Mostly they clean up well and can be resharpened, but the lead screws are encrusted and won't bite. With some difficulty I've been able to very carefully file the screw threads to some degree of sharpness, in a reasonably consistent spiral, to get them working. But I'm wondering if there's a better and more reliable way.



Here's a link that discusses cleaning up the lead screws with valve compound. I haven't tried it but it looks interesting -- perhaps some one here has and will weigh in.

www.cornishworkshop.co.uk/bracecleaning.html

[Eric Brown]

I have used the lapping compound in a starter hole trick and it works well.
I have also successfully used hardwood.
In addition I have found that almost any heavy liquid with grit in it will work. I've even used hand cleaner (Go-Jo, and other pumice types).

On some small bits and the double thread ones I have found that
small slitting files work and the smaller Japanese saw files too for sharpening.

One more thing to ponder is that all the bits taper with the cutting end the largest. This provides clearance for the bit. You can check this yourself with calipers. This also leads to a question as to if you file the ouside of the tip of the spurs more (until parallel) if you could bore smoother holes due to a burnising effect. Just thinkin'. Don't know. Yet.

Eric

[Steve Branam]

Ah, thanks, I'll have to try that! I have some aluminum oxide powder, as well as Gojo. I'll see if the local auto parts shop has grinding paste.

[jeff phillips]

Its pretty cool this how this thread has developed, as i am just starting to try and figure out how to drill the holes for the drawbore pins on my dining room table. I need to drill a 3/8 hole three inches deep in red oak. In looking to buy an auger bit, the ones lee valley sells are listed as being good for softwoods, and green hardwoods; however seeing as how my wood is neither, i really don't know what exactly to get, or where to get it. Can anyone point me in the right direction?

[Jim Koepke]

Jeff,

I think what you want is something with a double spur and a fine thread lead screw.

I do not know the rust hunting in your area, but if you get into Seattle much there should be at least a Restore and other shops that might be good places to visit.

I have seen a lot of good sets on ebay along with individual bits at times.

I work mostly with soft woods, but have drilled through oak and other hard woods without any trouble. The Lee Valley bits were single spur and looked like they were made to be used with cordless drills.

jim

[Eric Brown]

I agree with Jim about the double spur and fine thread. The most common set you will find is the Russell Jennings. (Number 100 set of 13).
This would get you from 1/4" to 1" by 16ths.

Look for a set original to the box and that all the cutting ends look good.
Then all you need is an auger file and a brace.

The file currently offered by TFWW is good.

As for brace, try to get one with ball bearing heads and chucks.
Lots to chose from here as to maker. Expect to pay between $30-100
for a good clean one. If you have the money, two braces are even better
and you can get different sweeps. Most common are 10 and 12 inch sweeps. If you plan on doing a lot of smaller holes or countersinking then a sweep of 6 or 8 inches work faster.

More tips: If an accurate hole is required, first bore a hole in a scrap block and then use it to guide your bit. If boring all the way through, stop after the screw start to protrude and then finish from the other side.

Eric

[Steve Branam]

I'll just put in my 2 cents for getting a Spofford brace. I picked one up for less than $20 at an antique store not knowing anything about it, and it immediately became my preferred brace, because it's so light and simple. I used it for the 3/4" x 3 1/2" holes in my Roubo bench. I see a couple for auction online at reasonable prices. The ones without the wooden grip are older.

I got a second one somewhere that ended up having a wobble in the end handle, so I haven't used it. I don't know if that can be corrected or not.

[Jim Koepke]

I got a second one somewhere that ended up having a wobble in the end handle, so I haven't used it. I don't know if that can be corrected or not.

After another Creeker mentioned this, I found a lot of my braces have a varying degree of wobble, mostly in the pad.

Turns out, all my Stanley's are OK as is the one Miller's Falls brace in my shop.

+1 on what Eric said about having multiple braces. If you are doing different sizes on the same job, it can save time. Also if you need one to countersink.

Then having the different sweeps is very convenient.

jim

[Eric Brown]

Steve mentioned Spofford braces as a good choice. I agree but,
they aren't the best choice if you only want one brace.

My reasons are for two simple reasons. First, they don't ratchet.
Second, they don't have universal jaw chucks.

While most boring could be done without a ratchet, there are times
when only a ratchet will work. Like in corners and other areas of limited access.
Another advantage of a ratchet is when boring large holes you can reposition the handle for maximum torque.

The reason for the universal chuck is that not all bits have the same size
square taper and there are times when round bits want to be used.

The Spofford though has a great feel and balance. It also gives a better
tactile feedback than most other brace designs. When buying a Spofford
look closely at the end that clamps onto the bit. See if the square socket
has been rounded out from years of use and also look at how the jaws close.
Sometimes the thumbscew is worn out. Best option is to try clamping a bit and make sure it is held solidly.

I collect (member of MWTCA & EAIA) and have over 20 braces, but there are several I tend to use more.
I like the Peck, Stow & Wilcox models with the Sampson universal ball-bearing chucks.
The Stanley 2101 series (Bell system) are also good. And yes, I like my Spoffords too.

Enjoy the slope. Eric

[Jim Koepke]

This is just an addendum to the original post and the thread.

One of the important parts of the auger bit is the spurs that score the wood before the cutting begins. They should be long enough to score a complete circle before the cutting lips start cutting into the piece being bored. This will help to prevent tear out at the top of the hole being created.

Another thing I do all the time when I am boring is to count the number of turns beginning when the cutting lips first start to make curls. With constant pressure and the same bit being used, I will know when the lead screw breaks through on the far side.

As an example, drilling 1/4" holes in some 3/4" fir takes 10 turns. Since these were being drilled for a carriage bolt, my desire was to just have the point break through. When the board was flipped, a 9/16" bit was used to bore the recess for the bolt's head. Of course, the turns were also counted on those so the bolt heads would all be recessed the same.

jtk

[Noah Barfield]

Thanks Jim and Harry--as I just bought a brace, this bit tutorial is exactly what I needed! I hope that this gets made into a sticky.

Noah

[Niels Cosman]

Great write up Jim!
You answered a lot of questions I hadn't even thought up yet!
cheers,
Niels

[Jim Koepke]

Great write up Jim!
You answered a lot of questions I hadn't even thought up yet!
cheers,
Niels


Thanks Jim and Harry--as I just bought a brace, this bit tutorial is exactly what I needed! I hope that this gets made into a sticky.

Noah

Glad you like it.

It is in the Neanderthal wisdom/FAQs stickey

http://www.sawmillcreek.org/showthread.php?103805-Neanderthal-wisdom-FAQs

It is under #10. Miscellaneous Tools

jtk

[Jim Koepke]

Here is a link to some more information posted in reply to a question about auger bits.

http://www.sawmillcreek.org/showthread.php?167266-Auger-bit-question

jtk

[lowell holmes]

My Irwins are 1960's vintage. I have nothing to compare them to. They will not fit a doweling jig.

[ian maybury]

Thanks for the input Jim, it's time over here for a bit of reading.

I did lots of boring with a bit and brace in my youth, but back then a hole was just a hole and I've no idea what the type was.

The point about horses for courses makes a lot of sense. I for example have a set of short Irwin Blue Groove power augers https://www.youtube.com/watch?v=eaW9Ll9rMwc, but was never been able to make much of them except for blasting holes through ceiling joists to run pipes and cables when setting up the shop. (which luckily was what they were bought for) No surprise when you look at the pitch of the flutes and the current advertising, but what's a pity is that they were for quite a while pushed in the UK woodworking mags as a fine woodworking solution. (makers in general no doubt chicken out so far as being too secific about applications is concerned)

Dieter Schmid in Germany has quite a decent range of (mostly power) augers, including Japanese made Star-M stuff which looks nice: http://www.fine-tools.com/schlangenbohrer.html Star-M catalogue: http://www.starminfo.com/en/catalogue/catalog.pdf

I bought a set of the augers he has on special offer as they look (and check out) as being decent, but realistically i'm not convinced that they will suitable for fine work judging by the way they are positioned in the catalogue. I haven't tried them yet, but presume the hex shank means they are intended for power use.

Boring in wood is in one way easy, but in another requires really sharp and precisely set up tooling to get clean entries and exits. Really good quality brad points like these Famag HSS-G are incredible http://www.fine-tools.com/holzspiralbohrer.html - so sharp you have to handle them carefully or you get nicked. No problem to drill even box store plywood cleanly - the nickers will actually trepann out a circle from the top veneer before they really start to cut.

Do you know if it's possible to get that sort of performance from a fine woodworking oriented power or bit and brace auger?

[Jim Koepke]

My Irwins are 1960's vintage. I have nothing to compare them to. They will not fit a doweling jig.

Most of my bits have been picked up at various places. There have been a couple of sets bought from ebay, but they can be hit or miss.

The Stanley/Handyman double spiral bits seem to be the closest to the actual size. Some of the old Stanley/Jennings pattern bits are also actual size. There are a couple patterns of the Russell Jennings bits. My recollection is there is a 100 series and a 32 series. My memory is fuzzy as to which is which.

Here is a link to an early Irwin Auger Bit pamphlet that covers a lot of different types of bits:

http://toolemera.com/pampdf/irwinhowtoPAM.pdf

jtk

[lowell holmes]

The Borechest is the set I have. It's a nice set. As I said earlier, I inherited it from my father. That set is not going anywhere.:)

[Jim Koepke]

Do you know if it's possible to get that sort of performance from a fine woodworking oriented power or bit and brace auger?

Looking at the page reminded me of what is likely most available to you may be metric sizes.

If an auger bit has sharp spurs that are long enough to scribe a complete circle before the lips of the spiral start to cut, then a clean hole can be bored. Of course for fine work, one has to be careful and remember to stop and come through the back side with care to obtain a clean looking hole.

Lee Valley has some interesting bits:

http://www.leevalley.com/us/wood/page.aspx?p=57713&cat=1,180,42240,53317&ap=1

These spoon bits often get used in my work.

jtk

[Reinis Kanders]

I have Lee Valley 3/4 inch brad point bit and as Ian says I can easily use a brace with it and make nice holes in plywood, etc, and it scribes a nice circle before going in.

[lowell holmes]

Following up on this discussion, I checked the diameters of some of the bits in my Borechest. They are as follows:

#16 ~ 1.022" od
#12 ~ 0.7612" od
#10 ~ 0.628" od
#8 ~ 0.522" od
#6 ~ 0.385" od
#5 ~ 0.322" od

It would be interesting to see if other bit makers had similar numbers.

[Hilton Ralphs]

Following up on this discussion, I checked the diameters of some of the bits in my Borechest.


Most of those are closer to whole Metric numbers than Imperial fractions. 26mm? Strange.

[ian maybury]

Not sure how it applies to bits for use in a brace, but i guess the other peculiarity about drills (and cutting tools) in general is that that depending on the geometry, how they are sharpened and the cutting speed they may not drill to their actually measured diameter. As the chip peels off the actual line of fracture may be displaced a little out from the cutting edge.

A little bit of a bend or runout/hand wobble for any reason will presumably also mess with tolerances...

[lowell holmes]

In another discussion, we were talking about auger bit diameters, doweling jigs and such. I commented that Irwin bits were 1/64" over size precluding their use in doweling jigs. Jim mentioned there are auger bits made for dowel. This indicates all auger bits are not created the same. I was just following up on that discussion.

[Jim Koepke]

#10 ~ 0.6211" od

That seems to be the only outlier in the group. All the others are a little oversize as would be expected with most auger bits. The #10 is actually undersized.

My first instinct would be to check and see if someone may have tried sharpening the spurs on the outside.

jtk

[lowell holmes]

or go back and check my reading. :)
I was confused on that reading. Actually it was 0.628.
That falls right where it should.
Go back to my earlier post. I corrected the readings.
I don't read a micrometer enough and sometimes I get confused.Can you imagine that?:confused:

[lowell holmes]

Jim,

How many lifetimes have you lived?

You can't accumulate that much knowledge in one. I am an old dog 84, and I know a lot. One thing I do know is that when SWMBO tells me to do something, I do not question her, I just do it and normally say Yes Dear!