Time-Saving Dado Gauge: Get Perfect-Fitting Dadoes Every Time
A stacked dado blade is one of the most useful accessories you can add to your table saw. From cutting simple rabbets and grooves to making box joints and other woodworking joinery, a dado set makes it easy to create clean, accurate cuts.
But there's one part of using a dado blade that can be frustrating: getting the width just right.
Whether you're cutting dadoes for plywood shelves or fitting hardwood parts into grooves, finding the correct combination of chippers and shims can involve a lot of trial and error.
That's why I made this simple shop-made dado width gauge. It takes a little time to put together, but once it's made, setting up my dado blade is faster and more predictable.
Why Dado Blade Width Matters
A stacked dado set consists of two outer cutting blades and a combination of chipper blades and shims that determine the overall cutting width.
Most dado sets include a chart showing which blade combinations produce standard widths.
The trouble is, those dimensions don't always match the material you're working with.
For example, plywood sold as 3/4" thick is often slightly thinner than its nominal dimension. If you set your dado blade to a full 3/4", the joint may end up too loose.
Even with solid hardwood, small variations in material thickness can affect the fit.
For accurate dado joinery, you want a slot that matches the actual thickness of the mating workpiece.
Make a Dado Width Gauge for Your Table Saw
Instead of repeatedly changing chippers and shims and making test cuts, I use a reference gauge with sample dadoes cut at different widths.
Each slot represents a specific dado blade setup.
To make the gauge, cut a series of sample dadoes using different combinations of chippers and shims.
As you make each cut, record the exact blade combination used to produce that width.
Be sure to identify both the chipper arrangement and any shims added to fine-tune the cut.
Over time, you can add new slots whenever you need a custom dado width.
The result is a handy reference that takes the guesswork out of future setups.
Find the Right Dado Blade Setup in Seconds
Using the gauge couldn't be simpler.
Whenever you need to cut a dado to match a piece of plywood or hardwood, take the workpiece over to the gauge.
Test its thickness in the sample slots until you find one that provides the fit you're looking for.
Then check the recorded blade combination for that slot.
You'll know exactly which chippers and shims to install without starting from scratch.
I still like to verify the setup with a test cut before cutting into my project parts. But the gauge gets me close to the correct width right away, saving time and unnecessary blade changes.
A Handy Reference for Accurate Dado Joinery
The best shop-made accessories are often the simplest ones.
This dado width gauge doesn't require complicated hardware or an elaborate jig. It's simply a collection of accurately cut sample slots with a record of the blade combinations used to make them.
Once you've built up a selection of common dado widths, you'll have a reliable reference for everything from plywood cabinet construction to hardwood joinery.
And the next time you need a perfect-fitting dado, you'll spend less time adjusting your blade and more time building your project.
More Woodworking Tips & Techniques
A simple dado gauge is just one way to save time and improve accuracy in the shop. Looking for more ideas to make your woodworking easier?
Explore our Tips & Techniques collection, featuring some of the best reader-submitted woodworking tips. From clever joinery methods and handy shop-made jigs to sharpening tricks and finishing techniques, you'll find practical solutions to everyday woodworking challenges.
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