September 4, 2020

What Does a Dado Blade Do?

Do you need wider grooves for your woodworking project? If so, a dado blade will do the trick. You might be wondering, “What does a dado blade do?”

Well, dado blades are specifically designed to cut wider joints and grooves.

A dado joint creates a durable bond with more area to glue if you build a bookshelf, door panel, or any other interlocking application.

What is a Dado Blade?

A dado blade is a kind of round saw blade that usually works with a table or radial arm saw. There are two types; stacked set and wobble blade. A stacked set has several round blades set on both sides of its removable clippers.

You can add chippers that will remove the excess material while you cut, which goes a long way toward smoothing out the dado.

A wobble blade does not “wobble,” per se, but instead sways to create an “S” pattern. This design allows for a custom cut and lets you adjust the lead on the blade quickly.

Dado Blade Sizes

The outer blades are usually 8 inches in diameter, but they come in 6 and 7-inches too. They’re 1/8 of an inch thick. An 8-inch cutter works for a 10-inch saw because it’s not for through cutting.


* 4 1/8 inches thick
* 1 1/16 inches
* 1 3/32 inches

Because of the range in sizes, the options of width are endless. While the broadest width achievable is 1 inch, anything less than that is easy to accomplish.

Types of Joints for Dado Blades

Depending on your project, certain joints will work better. A dado blade can produce four types of joints.

1. Rabbet

Rabbet joints include a dado cut or groove at the edge of the wood. This design allows for a second piece of wood to fit into the cut with the long side flush.

2. Dado Joint vs. Groove Joint

The difference between a dado joint and a groove joint is simple; with the groove joint, the joints run with the grain, while the first goes against it. A dado joint is a triple-sided channel that provides more surface to glue binding.

3. Half Lap

Half lap joints are known as halving joints. You remove identical amounts of material from two pieces of wood, about half its thickness, and join them together. Once aligned, you can glue both faces making for a stable hold.

4. Tongue and Groove

With this style, the “tongue” piece sticks out from one board and slides into another’s groove. The results are a perfectly flat surface that is strong, yet lets the wood expand and contract.

Working Without a Dado Blade

While it is possible to achieve a wider groove cut without a dado blade, it is more challenging. The dado blade creates perfect joints and grooves every time; and is a quick method.

If you wanted to, you could use a clamp guide with a miter saw or handheld router, but this would take longer, and the results would not be precise. Dado blades are compatible with most table saws and radial arm saws, but not all. Always check your model to make sure the dado blade is compatible with the saw.