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At my woodshop, a lot of the workbenches have holes in the tops.

Wooden workbench with two rows of round holes

I'm told these are for "bench dogs". What are bench dogs and how do they work? Why they're called "dogs".

  • 2
    You do have dogs in your photo. Plus, you have a nice bench clamp in there as well. (Which in the US is probably called a hold-down?) – Christopher Creutzig Apr 29 '15 at 20:01
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    @ChristopherCreutzig close; here in the US we call it a holdfast. – rob Apr 29 '15 at 22:23
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Bench dogs allow you to clamp a long workpiece that wouldn't normally fit in the jaws of the bench vise. There's a set of dogs that attach to the vise, and a set that attach on the table, essentially making one really big vise. One application would be holding down a board for hand planing.

enter image description here

(Image courtesy of Wikipedia)

They're usually in the form of pegs with a lip that sit in the pre-drilled dog holes and act as a stop. In the picture you included in your post, the brass pegs are the bench dogs. Note that they have a flat milled face to provide a better clamping surface. Other versions of wooden or plastic dogs are often square.

The reason there are multiple dog holes is so that varying length boards can be secured by selecting the right set of holes.

Pure speculation on my part, but they could be called "dogs" because they resemble a prairie dog popping out of its hole.

After a little Googling, turns out the engineering term "dog" is used for denoting a device to prevent movement. It is thought to be derived from how a dog (the animal) can bite and hold something. Add on that it's used in a bench, and there you have it. (I still like my explanation better.)

  • I wonder if you want to explain how they clamp a piece (i.e., by sandwiching it between the vice's bench dogs and the table's bench dogs or using friction for the black thingeys--can't think of their name). – dfife Apr 29 '15 at 18:40
  • en.wikipedia.org/wiki/Dog_(engineering) Ships "dog" their doors with handles that press the door firmly into a seal to make it watertight. I hadn't considered that it wasn't a purely nautical term. – Daniel B. Apr 29 '15 at 18:47
  • And it looks like you already modified your post with that XD Oh well. – Daniel B. Apr 29 '15 at 18:47
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In addition to bench dogs (explained well by Doresoom above), there are other devices that use the same holes. A holdfast uses the thickness of the bench to hold down a piece of wood with no additional clamps. You can also get a product called Wonder Dogs that let you apply pressure at odd angles. These combine with your bench to allow clamping work pieces of many shapes.

HoldFast

Wonder Dog and Wonder Pup

protected by Community Jul 2 '17 at 22:12

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