Sure, there’s more than one way to cut a mortise; you don’t have to buy a dedicated machine to do it. Still, I think a mortiser is the fastest way to get the job done. Unlike a router or chisel, a mortiser hogs out all the waste and squares the cut in one operation. If you build lots of tables, chairs, doors and face frames, you’ll appreciate this efficiency.
Are you planning to buy a new mortiser? If so, there are some nice benchtop options. I’ve rounded up seven here and cut mortises until my arm was sore. (Grizzly Industrial was also invited to participate but could not provide a mortiser in time for testing.) While all of these tools cut square holes well, one still bested the rest; it was a solid performer with an unbeatable price. Here are some thoughts about each model and a tip of the hat to my category winner.
Delta 14-651 Benchtop Mortiser
Craftsman 21907 Benchtop Mortiser
General International 75-050T M1 Benchtop Mortiser
Powermatic 701 Benchtop Mortiser
JET Tools JBM-5 Benchtop Mortiser
Steel City 25200 Benchtop Mortiser
Shop Fox W1671 Benchtop Mortiser
My Mortising Methodology
A mid-sized chisel was my choice for this test. I chucked a new, 3/8" chisel into each machine after carefully sharpening them. The chisels were obtained from an independent source to level the playing field in terms of chisel quality. I adjusted each cutter to create 1/16" of clearance between the auger bit and chisel; this provided consistency between the test tools and good chip evacuation. The depth stops were set for 1-1⁄4"-deep cuts. I cut four 6”-long mortises in hard maple, sugar pine, white oak and red cedar, in that order. All of the test pieces came from the same initial planks of stock. I felt they represented a good variety of hardnesses, densities, potentially tough grain issues and resin contents. In other words, realistic challenges for these mortisers. While I anticipated that hard maple and white oak would test these mortisers’ mettle the most, sugar pine actually posed the greatest challenge. Its resins seemed to make the chisels more prone to clogging and smoking than other woods. If a chisel was going to turn blue, here’s where it happened — although that only occurred twice. Still, even blued chisels were able to proceed from pine to oak and then cedar without a noticeable difference in sharpness or chip-clearing performance.