Joinery Selection Guide

Joint Strength Ranking

Not all joints are created equal. Here's how common joints compare in shear strength (resistance to being pulled apart) based on testing with PVA yellow glue in hardwood:

Joint Type	Relative Strength	Skill Level	Tools Needed
Mortise & Tenon	⭐⭐⭐⭐⭐ Strongest	Intermediate	Drill, chisel (or router)
Dovetail (through)	⭐⭐⭐⭐⭐ Strongest	Advanced	Dovetail saw, chisel
Box Joint (finger)	⭐⭐⭐⭐ Very Strong	Intermediate	Table saw + jig
Dowel Joint	⭐⭐⭐ Strong	Beginner	Drill, dowel jig
Biscuit Joint	⭐⭐ Moderate	Beginner	Biscuit joiner
Pocket Screw	⭐⭐ Moderate	Beginner	Pocket hole jig
Butt Joint (glued)	⭐ Weakest	Beginner	Clamps only

Traditional Joints

Mortise & Tenon

The king of woodworking joints. A rectangular peg (tenon) fits into a rectangular hole (mortise). When properly fitted and glued, this joint is stronger than the surrounding wood — the wood will break before the joint fails. Standard proportions: tenon thickness = 1/3 the rail thickness, tenon length = 4-5x the tenon thickness. For a 3/4-inch rail, the tenon is 1/4 inch thick and 1 to 1-1/4 inches long. Use for: table aprons to legs, door frames, chair joints, face frame construction.

Through Dovetail

The hallmark of fine craftsmanship. Interlocking trapezoidal pins and tails create enormous mechanical strength plus massive long-grain glue surface. The angled geometry resists being pulled apart in one direction — that's why drawers use dovetails (the tails in the drawer front resist the pull of opening). Standard slope: 1:8 for hardwoods, 1:6 for softwoods. Use for: drawer boxes, jewelry boxes, tool chests, case construction.

Half-Blind Dovetail

Visible from one side only — the joint of choice for drawer fronts where you want the front face clean. Same mechanical advantage as through dovetails but more difficult to cut because you cannot saw through to the other side. Use for: drawer fronts, cabinet corners where one face should be clean.

Dado & Rabbet

A dado is a groove cut across the grain; a rabbet is a groove cut at the edge. Neither is strong alone — they provide positive alignment and resist racking when combined with glue or screws. A shelf sitting in a dado will not slide forward under load. Standard depth: 1/3 to 1/2 the board thickness. Use for: shelving in bookcases, cabinet backs, drawer bottoms.

Modern Joints

Pocket Screws

An angled screw driven through a pocket hole in one piece into the adjacent piece. Fast and easy with a pocket hole jig ($30-150). The screw provides clamping force during assembly — no need for clamps. Strength is moderate and relies on screw thread, not glue surface. Joints can loosen over time with seasonal movement. Use for: face frames, quick cabinet assembly, shop jigs, projects where speed matters more than heirloom quality.

Biscuits

Compressed beech wafers inserted into matching slots. Biscuits excel at alignment (keeping boards flush during panel glue-up) but add minimal strength — edge-grain to edge-grain glue joints are already stronger than the wood. Biscuits are essentially alignment aids, not structural joints. Use for: panel glue-up alignment, mitered corner alignment, quick case assembly.

Dowels

Round wooden pins inserted into matched holes in both pieces. Stronger than biscuits because the dowel spans the joint deeper. Critical: hole alignment must be precise (a dowel jig is essential) and dowels must be fluted or spiral-grooved to allow glue and air to escape. Typical size: 3/8-inch dowels for 3/4-inch stock. Use for: edge-to-edge joints, frame joints, shelf supports, mid-range furniture.

Choosing by Project Type

Project	Primary Joint	Why
Dining Table	Mortise & Tenon	Handles racking forces and seasonal movement
Drawer Boxes	Dovetail or Box Joint	Resists pull force from opening, massive glue area
Bookcase Shelves	Dado + Screw	Supports vertical load, prevents forward sliding
Cabinet Face Frame	Pocket Screw or M&T	Speed (pocket) vs heirloom quality (M&T)
Cutting Board	Edge Glue Only	Long-grain to long-grain glue is stronger than wood
Picture Frame	Miter + Spline	Clean corner appearance with mechanical reinforcement
Jewelry Box	Half-Blind Dovetail	Clean front face, handmade quality signal

Glue & Reinforcement

PVA (yellow glue): The default for indoor furniture. Stronger than the wood itself in long-grain joints. Open time: 5-10 minutes. Apply thin, even coat to both surfaces. Squeeze-out indicates sufficient coverage.

Polyurethane (Gorilla Glue): Waterproof, good for outdoor joints. Foams to fill small gaps but has weaker bond strength than PVA in tight joints. Requires moisture to cure — mist one surface lightly.

Epoxy: Gap-filling, waterproof, strongest adhesive for poorly fitting joints. Expensive, messy, and hard to clean up. Use when joints have gaps or with oily tropical species that repel PVA.

Hide glue: Traditional, reversible (can be reheated to disassemble). Preferred by instrument makers and restorers. Long open time in liquid form. Excellent creep resistance.