Simple marking/cutting gauge with replaceable blades

I’ve seen a lot of homemade tools here that are beautiful and display a very high level of craftsmanship. I’m just starting out and trying to build up a set of decent tools, so the things I’ve been creating tend to be easy to make, effective, and cheap. I figure that there are other beginning woodworkers who are interested in tools like these, so hopefully this will help out.

This marking gauge is made from some scraps of red oak and about $1.50 worth of hardware, and it’s not too difficult to construct. All you really need to make it are a saw, a drill, and a chisel, although having a decent hand plane and shooting board is very helpful for squaring up and shaving down some of the wood. It uses common, 9mm snap-off blades for utility knives. You could probably get a lifetime supply for $5. If you wanted, you could use a nice laminated Japanese marking gauge blade, a pin, or a pencil lead, although you might have to shape the clamp a little bit to hold those things securely.

The design is somewhat inspired by Japanese marking gauges. They generally are made of oak and are pretty simple; they don’t have fancy features like brass wear plates. This one is set up to be pulled in the right hand, or pushed in the left, although changing it to work the other way is just a matter of flipping the beam around. The side of the fence that’s in the direction of motion is longer than the other side, because that’s the side that gets pushed harder against the workpiece to keep it square. I didn’t bother to shape this one, but I think that Japanese and Western marking gauges tend to have curved tops.

Probably the most challenging part is to drill a straight hole for the locking screw. I happen to have a drill press so this was easy for me. The second most challenging part is to cut out the rectangular holes for the beam and the square nut. For both of these, I drilled out most of the waste and chopped out the rest with a chisel. I learned that my nicely honed Irwin/Marples chisels would have visible nicks and indentations after just four mallet strikes going into red oak! I’ve heard that these newer China-made chisels aren’t as good as the older ones made in England. I’m not that experienced with chisels, but this seems surprisingly bad to me.

It’s important to make sure that the side of the hole that’s opposite the clamping block is flat, or undercut. If there are any bumps that stick up, that could allow the beam to rock back and forth. The beam should fit in the hole pretty snugly in the vertical direction as well.

If I were to make another one, I would probably make a few changes. I’d use a thicker piece of stock for the fence, because the 3/4” oak can easily split when you put in the 3/8”-diameter insert nut. That happened for me on a test piece, so I was very careful when I put this one in. I’d also extend the fence a little on the trailing side—I’ve found that with this design, I sometimes veer off a little bit at the end of a board because there’s less area of the gauge that’s registering on the workpiece.

I’ve heard that some people keep a lot of marking gauges around to hold different measurements. You could make a whole pile of these for the price of just one store-bought marking gauge. And if you ever need a big panel gauge, you could save yourself $70 by making it in your shop.

Here are the parts I used:
- 2 1/2×3 1/2×3/4” red oak (fence)
- 1/2×3/4×8” red oak (beam)
- a couple small pieces of wood for the clamping blocks
- 1” x 10-32 screw + washer + square nut
- 9mm snap-off blade
- 1 1/2” x 1/4-20 thumbscrew
- 1/4-20 insert nut
- a very small washer for the thumbscrew to push against so that it doesn’t dent the clamping block.

I hope this is useful for other woodworkers out there!