Dado Blades Deliver Productivity and Precision
Want to boost your joinery to the next level? A dado blade can help. Also called dado sets, these wide, adjustable blades are the big guns of the woodworking world. Spinning in your tablesaw, they create grooves and notches faster than any other joinery option. Useful with veneered plywoods, particleboard and medium density fiberboard (MDF), dado blades are also great for making first-rate tenons in solid wood, too.
If you think you need a dado blade, then you probably need a good one. What’s the point in creating rabbets and dados if their edges are chipped and frazzled? You’ll get best performance from professional-grade stacked dado sets. These create splinter-free cuts, even through delicate, veneered sheet goods. The term ‘stacked’ refers to multiple blades and spacers that come together on your tablesaw arbor to create the width of cut you want. By stacking different blades and chippers together, you can vary the width of today’s best dado blades in 1/32” increments.
Then there are the shims. These are ultra-thin disks of metal that fit between the blades and chippers, allowing you to further fine-tune cutting width by just a few thousandths of an inch each way. This is especially important when working with today’s undersized plywoods. So-called 3/4” ply is often a full 1/32” thinner than labeled. Shims as slim as 0.004” allow stacked dados to be tweaked to cut almost any width up to 7/8” in one pass.
Safety needs to be your priority with every tablesaw operation, but the rules are different when using a dado blade. The large width of blade means that splitters and anti-kickback guards can’t be used. This makes anti-kickback dado blade design that much more important. Not all models have this feature. Extra protrusions of metal in front of carbide cutting edges regulate the bite each tooth can take, greatly reducing the likelihood of kickback.
Cutting tenons with a dado blade? You’ll need to create a stop block so both shoulders of each tenon automatically have identical lengths. Your tablesaw mitre gauge and fence work together to make this happen, but they need help. Clamp a 3/4”-thick stop block far enough back on the fence so your workpiece fully clears the block as you slide it forward to encounter the blade. The resulting gap between the end of your workpiece and fence boosts accuracy and safety.
The height of your dado blade determines tenon thickness, but be careful. Since each tenon is produced in two passes (one for each side), you get twice the change in tenon thickness for every adjustment in blade height. Fine-tune saw settings on scrap that’s identical in thickness to your final workpieces before you prepare project parts.
Are you making multiple narrow parts with tenons on the ends of each? Start with a wide piece of wood, cut one long tenon across the entire end, then saw parts off with a regular blade. You’ll get identical tenons, guaranteed.
Dado blades are standard equipment in professional cabinet shops for the same reason they make sense in serious home workshops. Speed, accuracy and precision are something both amateurs and professionals can appreciate.
