If you want to cut perfect grooves and joints, having a dado blade will allow you to get the job done quickly and accurately.
While you can technically accomplish these cuts without a dado set, the job becomes more time consuming and complicated.
So what is a dado blade?
A dado is a circular saw blade for table saws to cut grooves into wood. When you see wood pieces with grooves or interlocking pieces, these are often accomplished with a dado blade. They’re used to provide slots for components to come together, such as door panels, shelves on a case, or drawer sides and bottoms.
Dado blade for table saws is a specialty item that is purchased separately. Keep in mind that not all table saws are compatible with a dado blade, so check your saw specifications before ordering one.
Conversely, if you know that you want to be able to use a dado blade and you’re in the market for a new table saw, make sure that the model you’re eyeing can accommodate this type of blade.
2 Different Types of Dado Blades
- Stacked dado blade set: This is a series of cutters stacked together that form a wider blade when assembled. You can think of it like a sandwich of saw blades. Between the stacked outer blades is a set of a removable chipper blades. They usually have about two to four teeth on them, depending on the manufacturer. They can be added or removed in order to obtain the desired width of the cut.
As you would probably guess, the number of chippers will determine the length of the cut. You can also intersperse the blades with spacers for even more fine tuning and precision. These shims come standard in any dado set and are made of either metal or plastic. Because of their versatility and high performance, stacked sets are the current standard in the industry.
- Wobble dado: This is a single blade that has an offset rotation, which allows you to get the same result as a stacked dado blade. It doesn’t technically wobble as the name suggests, but as it cuts it does sway back and forth in a curved “S” pattern within the confines of the plate. There are turning adjustments on either side of the blade, referred to as the outer plates, that allow you to determine the width of the cut.
By setting the amount of lead on the blade by rotating the outer plates and you can achieve custom cuts. Wobble dadoes are not considered as good, but they are less expensive. Wobble dadoes can also cause vibrations, making them a less favorable choice.
Stacked dadoes are the current standard. They typically cost between $50 and $100, though specialty sets can cost substantially more.
Keep in mind that you’ll also need a special throat plate that’s wide enough for the dado you’re cutting, and this piece of equipment usually has to be purchased separately.
What They Are Used For
Dado blades are used to cut grooves in material. The grooves form woodworking joints that are meant to connect two pieces of stock. They’re often used for cabinets, bookshelves, dividers, and drawers.
Though every woodworker has their own opinion on whether a dado blade is a requirement for their jobs, if you don’t have one, you’ll have to use a router table or a clamp guide in the middle of the board with a handheld router to achieve the same effect.
Miter saws are also an option for cuts that are traditionally made with a dado blade.
How Does a Dado Blade Work?
A stacked dado set will have two carbide-tipped outer blades that have a lot more teeth than the inner chipper blades. One of each of the outer blades must be installed on each side of the stack, and they’re not interchangeable.
Look for the label on each of the outer blades that says which one should be facing out.
Stacked dado sets have two outer blades that look like your standard run-of-the-mill saw blades. Between the two outer blades is a series of middle or cutter blades and these have fewer teeth. You can adjust the number of blades and shims you use to set the overall width of your cuts.
Most dado blade sets have 8-inch diameters for the outer blades. They’ll also typically include the following chippers:
- 4 1/8” thick chippers
- 1 1/16” chipper
- 1 3/32” chipper
The outer blades are 1/8” thick.
The different selections allow you to set up for just about any thickness you can imagine. The width of the cuts you can make will extend up to about an inch, and you can achieve nearly any size up to that threshold.
Depending on the manufacturer, the shapes can vary, being either star shaped or a full shape.
Most dado blade sets have a diameter of 8” for a 10” saw. Remember, this is because these blades are not used for through cuts. Instead, they’re designed to make a groove.
There are also smaller blades available, including 6” and 7” varieties.
As you add your chippers and blades to the stack, make sure that the teeth on the plates that are next to each other aren’t touching. Instead, they should be staggered. The teeth are designed to overlap slightly, but if they’re aligned, they tend to press up against each other and chip or break.
What Joints Can You Make with a Dado Blade?
Dado and Groove Joints
Dado joints are some of the strongest woodworking connections, and they’re easy to do with the right blade. They’re done by making a three-sided channel in one piece that runs across the grain of the wood and the other workpiece fits into that groove.
Because the inserted piece is captured on three sides, this cut offers incredible shear resistance. This cut also provides additional surface area for glue to bind.
These joints are often used for case good projects like cabinets and bookcases where shelves can fit into the sides of the structure and don’t need to move. They’re also common in drawer dividers, partitions, and a variety of other applications, making them a joint that every woodworker, from amateur to professional, should know how to build.
A rabbet joint is a type of dado cut that consists of a groove along the edge of a piece of wood that allows you to attach pieces flush with an item. The result is a piece of wood that has a lip that allows it to fit into a groove.
These joints create a visually stunning effect, creating the illusion that the material is made from one solid piece, when in fact it’s a series of components fitted together securely.
Rabbet joints are also idea for cabinet tops. Instead of just setting the top piece in with a butt joint, you can use the precision rabbet cut to slide it in place, with or without screws.
Tongue-and-groove joints allow two pieces of wood to join together and stay aligned in a single plane. The center tongue protrudes from one board and fits into the groove of an adjoining board. This creates a strong mechanical bond and is ideal for edge-to-edge joints. It’s also a useful joint because it allows the wood to expand and contract.
These joints are used primarily in flooring, paneling and parquetry. They’re essential for any application that requires two pieces of wood to be joined together while maintaining a flat surface.
When you need to connect two work pieces together that cross one another while keeping their faces flush, a half-lap joint is probably your best bet. This creates a stronger frame joint than you could get with a miter. It works by cutting away half of the thickness of two overlapping boards.
The name comes from the fact that half of the thickness of each of the work pieces is cut away. Then, they fit together to form one flat face. The pieces are interlocking and there’s also plenty of surface area left for glue, adding to their strength.
There’s a chance that you might not be able to get dado stacks if you live in the EU, which has been puzzling to woodworking enthusiasts worldwide. At the time of publication, you can still use them in home shops, but they’re not allowed in commercial shops. To add to the hassle, most, if not all, of the table saws available for sale in Europe have shorter arbors that aren’t long enough to accommodate a dado stack. Citizens get around this limitation by having a new arbor made, though not all saws can accommodate longer arbors.
Thankfully, dadoes are readily available in the US market.