Here’s how to make a simple jig that allows you to drill perfectly perpendicular holes that are the same depth every time.

Perpendicular Hole Drilling Jig:

  1. Cut two pieces of 1×4 scrap lumber the same length and square on each end, so when the drill chuck is held against the block, the drill bit protrudes the desired depth of the hole below the jig.
  2. Screw the two blocks of wood together to form a “T” shape.
  3. Position the drill bit on the stock, and hold the jig next to it.
  4. Align the drill bit with the inside angle of the blocks, and drill the hole.

Watch the video above to find out more.

Video Transcript

Joe Truini: One of the challenges of drilling with a cordless drill is how do you know when the bit is perfectly straight so you get a perfectly straight hole?

Well, you may have seen this trick before where you can take any square block of wood—in this case a two-by-four—and you hold it in place. And you put the bit up against it—you align the bit with the block—and now you know you’re perfectly straight. Right?

That’s a great tip, except what about this direction? It doesn’t help you with this direction, only in one direction. So here’s a better idea.

I just took a couple of little pieces of one-by-four. I screwed them together to form this inside angle—that’s what you need, that inside corner. And now, when you put the bit in place—the drill—and you hold this jig up against it, you put the bit right in the corner.

And now, as you can see, it’s being held in both directions—perfectly square—and you just drill your hole.

And if you cut the block the right length, which I did here purposely. And you see I have three-quarters of an inch sticking out, and that’s exactly what I need—a three-quarters-inch deep hole.

And so I can just drill down. And when the chuck hits the top of the jig, your hole is done.

Further Information

Editorial Contributors
avatar for Joe Truini

Joe Truini

Radio Show Co-Host

Joe Truini is a contractor, author, and the host of “Simple Solutions” on Today’s Homeowner TV and the weekly Today’s Homeowner radio show. He has worked on both large commercial projects and residential remodeling, and has written for national publications such as This Old House and Popular Mechanics. He has also written eight books, including three best-selling shed-building books. Joe lives in Connecticut with his family and enjoys hiking, traveling, and baseball in his spare time.

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