Do you want to realize the full joint-making potential of your table saw? Then buy a quality stacked dado blade. When it comes to joinery, only a router can surpass a table saw and dado blade for versatility. With a dado blade, you can mill a variety of rabbets, dadoes and grooves, tenons, both parts of a tongue-and-groove joint, spline slots, box joints and a slew of different lap joints — all from this one multi-piece blade accessory.
While I was collecting these premium 8" models for testing, I recalled my first dado blade from 20-some years ago. It consisted of a pair of wobbling blades on an adjustable hub — a regrettable performer. I could rarely dial it in to get a proper flat-bottomed dado, and the top “show” edges of the cuts were often ragged messes. That all changed when I upgraded to a quality stacked set. By swapping chipper blades of varying thicknesses, I could easily achieve any cutting width I wanted. The bottoms were dead flat — just what you’re after when machining interlocking joinery — and the top edges were very tidy. It was an astonishing and instant improvement.
These days, premium dado blades abound, and hearty competition between blade makers means you can get professional results from many different sources. This test group consists of the best of the best, so I wasn’t surprised to see some stellar results ... but picking an overall winner was perplexing. More on that later. Here’s how the test went and what I thought after the chips flew.
Making Tracks, Earning Stripes
We woodworkers want to buy only one dado blade that cuts it all well — from composite sheet materials to both softwood and hardwood, so I made test cuts on all three material types: black melamine particleboard to evaluate edge chipping, oak veneer plywood and cedar to inspect for splintering, and some hard maple. I cut as many 5/8"-wide, 3/8"-deep dadoes into 2 x 2 ft. sheets as I could fit on the melamine and across the veneer of oak ply.
Next, I made 25 cross-grain cuts on 1 x 8 cedar; all of these cuts were made on a 3-hp cabinet saw with workpieces resting in a crosscut sled. Then I stacked the full marks in the bottoms of the load of chippers onto each blade to adjust for maximum width and cut three grooves in hard maple. It was a good way to evaluate bottom and sidewall smoothness with all parts in place. After making my test cuts, I used a low raking light to inspect the test pieces closely.
Who Makes Top Cut?
Typically when I conclude a round of testing, a tool stands out in my mind almost immediately as pick of the litter. It outperforms the others, sells for a fair dollar and is rich with features. This time, three blades left this strong impression: Amana, Freud and Infinity. In cutting tests they ran a neck-in-neck race, and they’re priced the same. We don’t award multiple “Best Bet” awards, but all three of these blades deserve that prize. There are so many consistencies between this trio, it would be unfair to pick just one as the overall winner.