Four tools cut a mortise and tenon: a mortise gauge to mark both halves, a chisel, a mallet and a backsaw. If you buy one thing first, buy the chisel set — the Narex Richter is the one we rank highest — and if you buy one thing to make the joint fit, buy the mortise gauge. That is the honest list for anyone building a table, a chair, a door or a frame-and-panel anything.
Everything else on this page is a speed upgrade, not a capability upgrade. A drill press and a Forstner bit remove mortise waste faster than a chisel. A dado stack cuts tenon cheeks faster than a saw. A dedicated mortiser does the whole mortise in one operation. None of them makes the joint better; they make it quicker, and they matter once you need twelve of them instead of two.
Why the gauge is the tool that decides the fit
A mortise and tenon fits when the tenon's cheeks and the mortise's walls are the same distance apart. The way to guarantee that is not to measure twice — it is to mark both parts with the same tool at the same setting. A mortise gauge has two cutters on one beam; you set the spacing once, to the width of your chisel, and scribe the mortise on the stile and the tenon on the rail without ever touching the adjustment.
Marked that way, a joint that fits is the default rather than a good day. Marked with a rule and a pencil, you are relying on reading the same number twice on two different pieces, which is where the slop comes from. This is the same principle we lay out in how to use a marking gauge, applied to the one joint where it pays most.
The chisel does the work, and its width sets the joint
Mortise width is conventionally about one third of the stock thickness, but the number that actually governs it is the width of the chisel you own. Cut the mortise to a chisel width and the walls can be pared straight with that same chisel; cut it to an arbitrary dimension and every wall is freehand.
A bench chisel set covers this. A dedicated mortise chisel — thick, square in section, made to be levered in a deep cut — is a genuinely better tool for deep mortises in hard timber, and we will say plainly that our registry does not currently carry one; the bench chisels below are what we rank and what most shops use. Take light cuts, do not lever hard against a bench chisel's side, and the joint comes out the same.
The seven tools on this page, and what each is for
- The chisel set: Narex Richter bevel-edge chisels. Chopping the mortise, paring the walls, trimming the tenon shoulders.
- The gauge:the iGaging mortise gauge, with twin cutters and micro-adjust — the tool that makes both halves agree.
- The mallet: the Narex 16 oz beech mallet. A hammer on a chisel handle splits it; a mallet does not.
- The saw:the Spear & Jackson 12 in. tenon saw at 15 ppi — a backed saw, because the stiff spine is what keeps a cheek cut flat.
- The tenon shortcut: a Freud SD208S dado stack, which cuts tenon cheeks and shoulders on a table saw in four passes.
- The mortise shortcut: a Freud Forstner set, for drilling out the waste before you chisel the walls clean.
- The machine answer: the JET JBM-5 benchtop mortiser, which cuts a square hole directly and earns its bench space only in volume.
If what you want is the joint itself rather than the kit — proportions, the mortise-first rule, how to rescue a loose tenon — that is our mortise and tenon guide, and the hand-tool method is in how to cut a mortise by hand. Prices below come from our live price feed and carry the date they were pulled.
The seven side by side
Published listing specifications for the seven tools above, grouped by the part of the joint they serve. The "route" column is the one to read first: the first four tools are a complete kit on their own.
| Tool | Part of the joint | Route | Published specifications |
|---|
| Narex Richter chisels (5) | Mortise walls, tenon shoulders | Hand | Cr-V steel, claimed 62 HRC, ash handles |
| iGaging mortise gauge | Marking both halves | Both | Twin cutters, micro-adjust, 1/32 in. and 1 mm scales |
| Narex beech mallet | Driving the chisel | Hand | 460 g / 16 oz, beech head, one-piece turned |
| Spear & Jackson tenon saw | Tenon cheeks and shoulders | Hand | 12 in. blade, 15 ppi, backed, push stroke |
| Freud SD208S dado set | Tenon cheeks | Table saw | 8 in. / 12T, 1/4–7/8 in. range, 3 chippers + shims |
| Freud PB-107B Forstner set | Mortise waste | Drill press | 7 bits, 1/4–1 in., serrated shear rim |
| JET JBM-5 mortiser | Whole mortise | Machine | 1/2 in. chisel capacity, 4-3/4 in. stroke, 115V |
Mortise first, tenon second — always
A mortise is a hole with fixed walls; once it is cut, its width is whatever the chisel made it. A tenon is a projection you can keep shaving. Cut the mortise first and you can fit the tenon to it with a shoulder plane, a chisel or a few saw strokes. Cut the tenon first and your only adjustment is to widen the mortise, which is the harder of the two operations and the one where a slip shows.
The same logic governs depth. Make the mortise about 1/8 in. deeper than the tenon is long, so the tenon seats on its shoulders rather than bottoming out, and so there is somewhere for excess glue to go rather than hydraulically holding the joint open.
Proportions, in one paragraph
The conventional proportions are a tenon about one third the thickness of the rail, as wide as the rail allows minus a shoulder at each edge, and long enough to reach two thirds to three quarters of the way through the stile. A haunch — a short stub of full-width tenon at the top — stops a rail twisting in a frame and fills the groove in a frame-and-panel door. None of this is arbitrary: it keeps enough meat either side of the mortise that the stile does not split.
Which shortcut to buy first, if you buy one
If you already own a drill press, the Forstner set is the cheapest real speed-up on this page: drill a line of overlapping holes to depth inside your gauge lines, then pare the walls with a chisel. You are chiselling air instead of wood, and the wall accuracy is still yours.
If you already own a table saw, the dado stack is the better buy, because tenon cheeks are the fiddly half of the joint by hand. A stack set to the shoulder depth, with the rail flat on the table and a miter gauge behind it, cuts both cheeks and both edge shoulders in four passes with identical setups. Our dado blade set roundup covers the family, and best miter gauge covers the thing that actually holds the rail square while you do it.
The benchtop mortiser is last for a reason. It is a real machine that does one job well, it wants bench space and a dedicated chisel per width, and it stops being a luxury somewhere around the point where you are cutting a dozen mortises for a set of chairs. Below that, the chisel wins on every axis except speed.
Where these numbers come from
The steel grades, hardness claims, blade lengths, tooth counts, bit diameters, capacities and strokes above are the manufacturers' own published listing specifications, recorded when we researched each tool and cited per product in Sources. We have not measured edge retention, joint strength or cut accuracy in a lab — we do not have one, and our methodology page says so plainly. Prices come from the live price feed and carry the date they were pulled.
