A dovetail jig is a woodworking guide that helps a router cut matching pins and tails for strong corner joints. Dovetail joints matter because their wedge shape resists pulling apart, making them useful for drawers, boxes, and cabinets. The jig holds the boards at a fixed position while a template guides the router bit along precise paths.
This turns a difficult hand-cut joint into a repeatable machine-guided process.
Key Facts
- A dovetail joint uses angled tails and matching pins to resist tension and sliding.
- Joint strength increases when mating surfaces fit tightly and glue contacts clean wood.
- Common dovetail bit angle values include 7 degrees, 8 degrees, and 14 degrees.
- Depth of cut must match the jig setup: cut depth = board thickness for many through dovetails.
- Router speed should match bit diameter: larger bits generally need lower rpm.
- Template spacing sets the pitch: pitch = distance from one tail centerline to the next.
Vocabulary
- Dovetail jig
- A clamping and guide system that positions wood and directs a router to cut dovetail joints accurately.
- Router
- A power tool that spins a cutting bit at high speed to remove wood along a controlled path.
- Dovetail bit
- An angled router bit shaped to cut the sloped sides of dovetail tails or sockets.
- Pins and tails
- Pins are the narrow projecting parts on one board, and tails are the wider wedge-shaped parts on the matching board.
- Template guide
- A fixed pattern on the jig that controls the router movement so repeated cuts have the same shape and spacing.
Common Mistakes to Avoid
- Setting the router bit depth by eye is wrong because even a small depth error can make the joint too loose or prevent it from closing fully.
- Clamping the boards out of square is wrong because the pins and tails will be cut at a skewed angle and the corner will not align.
- Moving the router in the wrong direction is wrong because climb cutting can grab the bit, damage the wood, and reduce control.
- Skipping test cuts is wrong because wood thickness, bit height, and template position must be verified before cutting the final workpiece.
Practice Questions
- 1 A jig spaces dovetail centers 18 mm apart. How many full dovetail centers fit along a 216 mm drawer side?
- 2 A through dovetail setup requires a cut depth equal to board thickness. If the board is 19 mm thick and the current bit depth is 16 mm, how much must the bit be raised?
- 3 Explain why a dovetail joint can resist being pulled apart better than a simple butt joint, even before considering glue.