in-DEXABLE Joiner's Combination Squares - Shipping July 2025

The Blue Spruce Toolworks in-DEXABLE Joiner's Combination Squares combine 90° with traditional dovetail angles. Since their introduction in the late 1800s, combination squares have always “combined” 90° and 45°. That’s great for trimming windows and making picture frames, but when you’re working on classic joinery, you need something completely different. Blue Spruce has broken the mold by combining the angles you need for hand-cut dovetails with a meticulously milled 90° face. But we didn’t stop there. We also loaded these squares with features that improve and simplify all types of joinery layout.  

We packed these versatile, accurate squares with features that will make them the tool you’ll reach for all the time. The laser-engraved scales lock in to the head at each full inch (or every 30mm on the metric versions). Need to set your router bit? Lock the indexing pin at the end and the scale is zeroed out perfectly to the outside of the head. Now the scale can stand upright by your bit for accurate adjustment.  

We laser-cut scribing guides into the blade every sixteenth of an inch (every 1mm on metric). Just engage the push-button indexing pin at any full inch along the scale, drop your pencil in the correct notch and slide along the edge of your stock for perfect parallel lines right where you want them. This feature makes mortise and tenon layout a breeze. 

There’s a sliding tab that extends from the head to support the square on the edge of your stock. It slides both ways, supporting the head when marking either dovetail lines or square lines. 

When you’re laying out dovetails, everything you need is right in your hand. The first step is to strike the baseline using the square side. We suggest you use a marking knife (and we make a really nice one). It will give your chisel a positive reference when you’re ready to cut out the waste.

Once you’ve laid out your spacing, square each cut line across the end of your stock. Then switch to the angled side of the head and lay out the cut lines for your tails. The heads are available in 1:6, 1:7 and 1:8 ratios. In general, 1:8 is favored for hardwoods, with the other two, steeper angles favored for softwoods, but there are no hard and fast rules…use what looks best on your project. 

The three dovetail ratios can be paired with any of three blades...4", 6" and 8". Heads and blades are available individually, or if you want to be ready for anything, get the Deluxe Joiner’s Combination Square Set which includes all three heads, all three blades and 3 wall-mountable Rack-Its™. 

Like all Blue Spruce products, the in-DEXABLE Joiner’s Combination Squares are precisely machined and carefully inspected in our Strongsville, Ohio facility (just south of Cleveland).

*NOTE BODIES AND BLADES ARE SOLD SEPARATELY

*Note, imperial heads fit imperial blades only, and metric heads fit metric blades only.

Shipping July 2025.