Bench Dog Hole Size

[Tim Nguyen]

I am in the process of building my bench. The bench is laminated pine about 4 inches thick. I have decided upon 3/4" holes for dogs and other bench accessories.

I am using a bit brace and WoodOwl 3/4 (19mm) bit to drill the first few test holes.

I have found the holes really tight for 3/4 inch dowels from the big box stores. I just got in some Veritas 3/4 wonder dog and found that they are also very tight. I can not move them without hitting them with hammer. It makes adjusting them a chore. Questions:

1. Using 3/4 inch auger the wrong size? Should I be using 13/16 which is the next size up? Seems everything I read is to use 3/4 size bit, which is making me doubt myself.
2. layout? I am planning to space out the dog holes 5 inches apart which is a little bit less than the wonder dog reach. Opinions?
3. I will most likely place at least two rows of holes. Spacing from the front of the bench. Second board in or several boards in?

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I haven't trim the bench to it final dimension yet and found it useful to make experiment on the future cutoff. Hence I tried a 7/8 inch hole. Way too big.

[Jim Koepke]

One of the confusions about this comes from metric conversions. Some treat 18mm as equal to 3/4" and others use a 20mm equivalent. In reality 19mm is an almost exact match. Some folks just do not like odd numbers.

My Sjöberg bench has 18mm holes. All the extra holes have been drilled with a 3/4" auger.

You may need to drill some test holes in scrap to see what works best for the accessories you employ.

My dogs tend to get made on my lathe to 3/4" and work well. Most of the original holes on my bench have been run through with a 3/4" auger.

jtk

[Erich Weidner]

My Sjöberg bench has 18mm holes. All the extra holes have been drilled with a 3/4" auger.

jtk

Oh for the love of all.... is this why all of my Veritas 3/4" dog hole accessories don't fit and why when I filed a few out a bit the Veritas stuff fits, but now the plastic dogs that came with the bench fall right out?

I'll be checking that tomorrow with the dial calipers... (Gods I hate that bench, just one more new reason to hate it. Hate I say! :) )

[David Eisenhauer]

I used a 49/64" bit to drill my holes after finding that 3/4" was too tight. I will probably never use it for anything other than what I used it for but it worked perfectly for that use.

[Stephen Rosenthal]

Tim,

Maybe this will help. It’s for 1” holes and uses a Wood Owl augur and a cordless drill. Very clever and the same principle can be applied to 3/4” holes. https://blog.lostartpress.com/how-to-drill-ream-a-holdfast-hole/

If you have at least a 2HP (3+ is better) plunge router and a 3/4” straight or up spiral bit, you can fashion a jig out of thin MDF that clamps to the bench and holds the router in place while you plunge into the bench surface at the exact position of your intended holes. Simply trace the baseplate of your router to the MDF and cut out an exact opening with a coping saw to house the router and prevent it from wandering. If you plunge about 3/4-1” you can then finish with a brace or cordless drill and augur bit and be guaranteed a straight hole.

[chris carter]

I drilled all my 3/4" holes with a 3/4" auger bit by hand. They don't need to be absolutely 90 degrees. Anything close to that is fine and you will never notice. I certainly can't tell which of mine are 90* and which are 89.5*. My dogs are made from store bought 3/4" dowel and yes, they were a very tight fit because well, they are both 3/4" I just grabbed a rat tail (round) file and spent 30 seconds on each hole to loosen them up a bit. You could also take the opposite approach and sand down your dogs.

[Jim Koepke]

I drilled all my 3/4" holes with a 3/4" auger bit by hand. They don't need to be absolutely 90 degrees. Anything close to that is fine and you will never notice. I certainly can't tell which of mine are 90* and which are 89.5*. My dogs are made from store bought 3/4" dowel and yes, they were a very tight fit because well, they are both 3/4" I just grabbed a rat tail (round) file and spent 30 seconds on each hole to loosen them up a bit. You could also take the opposite approach and sand down your dogs.

My understanding is if the top of the dog hole has a slight lean toward the tail vise that is fine.

My dog holes are mostly at 90º and work fine. My dogs have an angled flat on the face:

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If there is a little play in the hole the face of the dog still has a bit of slope to hold items securely.

jtk

[glenn bradley]

As you've noticed, 19mm is under 3/4". You're in GA, why not use a 3/4" bit? I'm a hybrid ww-er so I use a 3/4" Forstner to give me about 1/8" deep hole then position and finish with a 3/4" spiral router bit. Dowels often vary widely from the stated diameter but, I have made several dogs and other dog-use items with red oak 3/4" dowels.

Here's a pic from an old bench but,

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my current bench holes were done the same.

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The dowels are hit and miss but, a little touch up on the problematic dowel in the sticky spots and all is well. Aftermarket items (brass, aluminum, steel) that are for 3/4" all fit fine.

[Bob Jones 5443]

Use the 3/4" auger and make your own dogs from 3/4" wood dowel and a bit of poplar board. If they're tight you can sand and wax them. Mine are made from about 2-1/2" of dowel glued into a 3/4" Forstner hole in a 1-1/2" x 1-1/2" by 3/8" thick chip of poplar. I angled down the edge of the flat chips slightly, and the dogs hunt. Cheap, too. I've been using the same six dogs since 2008.

In California I don't run into serious wood movement, but every once in a while I rub a little candle wax on one and twist it into a dog hole. My bench is 2-1/4" thick.

When I need to plane work thinner than 3/8" I put it up on a flat platform 1/8" or 1/4” thick or so, and the dogs do the job then, too.

[James Pallas]

I just had occasion to drill 15 dog holes to fit Veritas bench dogs. I have 4 new dogs. I measured them all between .741 and .742. I made a test hole with three different bits and decided on the one I liked best for the fit. I didn’t measure at the time just test fit. Today I measured the dogs and the bit and the hole. The bit measured.749. The hole measured .752. Some slop or movement of the portable guide I would guess. The fit is good snug but moves by hand. Just for info.

[Jim Koepke]

As you've noticed, 19mm is under 3/4". You're in GA, why not use a 3/4" bit?

19mm is ~0.002" under 3/4". Tim is using a Wood Owl bit. Wood Owl bits are made in Japan. My guess would be the Wood Owl bits are made to a metric specification.

Most old auger bits are ~0.015" over their nominal size.

When buying dowels my tendency is to buy the 'fat' ones if they are going to be used for doweling. If they were being bought for dog holes my choice would be to buy the 'skinny looking' 3/4" dowels.

Otherwise one might have to devise a way to sand down the dowel. The other approach is to enlarge the hole slightly with a round file or other tool.

jtk

[Tim Nguyen]

That is the crux of the problem. WoodOwl is slightly undersized. Interesting that true 3/4 is slightly over sized. I think best bet is to go 1/16 bigger or find a true 3/4 auger.

[fritz eng]

I carried a digital caliper with me when i went to the big box store and measured what I knew was the correct size dowel or slightly smaller. I was surprised at the variation in diameters even though they differed by a few thousandths of an inch. Just be aware that your dowels can still change with the humidity depending on where you live in the Staes.

[Derek Cohen]

The easiest solution (not necessarily cost-effective) is to use a 3/4" twist bit in a cordless drill to drill out the existing holes. All the hard work has been done by the auger bit, and now you just want to re-size it slightly. Do not be tempted to use a different type of drill bit or a round file as it will be difficult to keep these running straight.

Regards from Perth

Derek

[Jim Koepke]

That is the crux of the problem. WoodOwl is slightly undersized. Interesting that true 3/4 is slightly over sized. I think best bet is to go 1/16 bigger or find a true 3/4 auger.

If you have the bit, test it in a piece of scrap 2X material before drilling a bunch of holes.

Not all augers bits are oversize. The average auger bit is ~1/64" (0.015") oversize.

There are auger bits sized dead nuts on to their marked sizes:

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Some of my Stanley Handyman auger bits are also right on the money for size. They are double spiral like Jennings pattern bits but have wider side lands. The #6 (3/8") is my favorite for many dowel applications.

jtk

[Norman Pirollo]

This comes up often as an issue with 3/4 in. dowel stock. I tend to select the smaller diameter stock if there is an assortment available. I would rather not mess with perfectly sized 3/4 in. bench holes. If length of dowel is a tight fit in the hole, I wrap some sandpaper around the dowel length and turn it a few passes with progressive grits from 120 to 220. This is what I do for my bench jigs. For individual bench dogs I undersize the length of dowel forming the bench dog using sandpaper wrapped around the length. Once bench dog fits a tad loose ,,I drill and insert a bullet catch into the side . This works extremely well and keeps bench dog from falling through yet maintaining a tight fit at any height. I like this approach as it makes the bench dog much more versatile in different dia. 3/4 in. bench holes.


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[Tim Nguyen]

This is an innovated method to secure the bench dog. I have to take a look at that.

[Jim Koepke]

This is an innovated method to secure the bench dog. I have to take a look at that.

Mine are sometimes used on a saw bench with a top of 2X material. For those it helps to have the bullet catch closer to the flat. Otherwise when they are in the down position the might fall out.

jtk

[Joe A Faulkner]

I used. 3/4” router bit. This resulted in good fit for both Veritas bench pup vise and and Gramercy hold fasts. My wooden dogs are flat one side with a wire spring. The bullet catches look much nicer. I spaced my holes every 4 inches and have no regrets

[Tim Nguyen]

Update for me:

I ended buying a vintage set of Russel Jennings augers. These are stamped Stanley made in England, so I am not sure of the quality. My original concern of buying vintage came to roost.
The Russel Jennings set aren't sharp out of the package. The spurs aren't cutting as well. The augers aren't pulling itself through the wood. The augers stops when the spurs starts to dig into the wood. There were a few that seems to work well, but the crispness of the cut wasn't as good.

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Comparing the modern WoodOwl to the vintage RJ augers, the WoodOwl cuts more crisp holes and faster. The 3/4 RJ were over-sized at .78 inches versus the WoodOwl 0.74 inches measuring with a caliper. Waiting on getting a auger file before making more test cuts.

[steven c newman]

I used a #13 bit, in a 12" sweep Samson #8012 brace. That way, I could taper 7/8" dowels for a snug fit.

Bit was an almost minty Craftsman bit....

[Jim Koepke]

Tim, Here is a booklet you may want to download > https://www.toolemerapress.com/2019/09/museum-books-how-to-select-use-and-care-for-bits-1939-the-irwin-auger-bit-company.html

Even though it is an Irwin booklet it has sharpening information that applies to any brand of auger bit.

jtk

[Tim Nguyen]

Thanks for the link! Finding a auger file seems a little crazy right now. Anybody has a particular brand file they recommend? Amazon offers two. Highland woodworking has one, but both Lee Valley and toolsforwoodworker are out of stock.

[Jim Koepke]

You might try Home Depot > https://www.homedepot.com/p/Rack-A-Tiers-Auger-Bit-File-AUFILE/303355467

These may have to be special ordered. They may be in the stores.

Everything is going crazy on pricing. It was my good fortune to find a few new old stock Nicholson brand auger files in a fastener/tool store at a great price.

If you have specialty machine supply shops, welding supply shops and such it might be a good idea to give them a browsing. It is surprising all the useful items that may have been sitting on the shelves for a few years.

jtk

[Derek Cohen]

Update for me:

I ended buying a vintage set of Russel Jennings augers. These are stamped Stanley made in England, so I am not sure of the quality. My original concern of buying vintage came to roost.
The Russel Jennings set aren't sharp out of the package. The spurs aren't cutting as well. The augers aren't pulling itself through the wood. The augers stops when the spurs starts to dig into the wood. There were a few that seems to work well, but the crispness of the cut wasn't as good.

434343434344

Comparing the modern WoodOwl to the vintage RJ augers, the WoodOwl cuts more crisp holes and faster. The 3/4 RJ were over-sized at .78 inches versus the WoodOwl 0.74 inches measuring with a caliper. Waiting on getting a auger file before making more test cuts.


Tim, there are two factors here. Firstly, the Wood Owl are new and the RJ likely have dull cutting edges. You may need to sharpening these. There are m any videos on Youtube that will show you the way. But there is a second factor, and I would explore this first: if the wood is hard, the lead screw may not be able to cut its way into it. There is a way around this - drill a pilot hole slightly narrower that the lead screw. This will reduce the work it is required to do. The auger may cut like it is sharp. If not, then go to point one.

I posted this a short while back ...

https://i.postimg.cc/Gh2q9NDt/8a.jpg

https://i.postimg.cc/TY4Qb9j9/9a.jpg

https://sawmillcreek.org/showthread.php?282856-Hold-downs-and-augers

Regards from Perth

Derek