We get a lot of questions about which Benchcrafted Tail Vise to purchase, left-hand or the right-hand model.
There is some confusion about the differences between the two. This should clear it up.
First of all, the screw in both vises is identical. They both turn the same way to adjust the vise. Clockwise to advance the dog block, counterclockwise to open the vise. Typical righty-tighty stuff. The sliding plate assembly is the part of the vise which determines the handedness. The right-hand and left-hand versions are simply mirror images.
Here you can see the difference. This is a right-hand vise.
And this is a left-hand vise.
Either vise can be used in either end of your bench.
Two factors determine which vise to choose:
1. Obviously the first is your dominant hand--in other words, which end of the bench you'll install the vise. If you're left handed, you'll install the vise at the left end of the bench, and vice versa.
2. Dog-hole placement in your bench, that is, how far back from the front edge the holes fall.
We'll focus on the second factor, since the first one is a given.
We recommend that when building a new bench you place your row of dog holes as close to the front of the bench as possible. This makes working narrow boards more convenient. But with benches with flush-to-the-front and thick legs, this usually places a dog hole right over a leg.
The solution is to drill a cross hole through the leg directly below that dog hole so you can access the dog (see above). You'll also need to continue the dog hole down through the leg so it meets the cross hole.
If you don't want to hassle with this step, or you're retrofitting a vise to a bench that already has dog holes far into the bench top (past the leg), you'll want to choose the opposite-handed vise for your installation. Using the "wrong" vise in this situation will place the handwheel closer to the front edge of the bench than if you had used the "correct" vise.
Let's look at some pictures to illustrate.
This is a right-handed vise installed in a right-handed bench. Notice that the handwheel (and screw) fall behind the dog holes.
This is a left-handed vise installed in a left-handed bench. The handwheel and screw again fall behind the dog holes.
Here's a classic example of using the "wrong" vise because of dog-hole placement. This is Christopher Schwarz's Roubo bench. He installed the vise as a retrofit. His dog holes are positioned far from the front edge of the bench, about 6" back so they clear the legs. He installed a left-handed vise in a right-handed bench. This places the handwheel and screw in front of the dog holes. This makes the vise more convenient to use since the handwheel is closer to the front of the bench.
This is what it looks like from the underside.
Using a mirror image of Chris' bench, we can see what the same arrangement looks like in a left-handed bench. This is a right-handed vise installed in a left-handed bench. Again, the handwheel is positioned closer to the front of the bench for convenience.
From the underside.
For some more info on Chris' installation and templates click here.
Hopefully this will clear up any confusion about which vise to get. If you have any questions, please leave it in the comment section.