Drilling Jig

The drilling jig: drill straight, at the right diameter, the first time.

Drilling seems simple — until the bit slips, the hole is too wide for the screw, or off by two millimeters that ruin the assembly. The drilling jig solves all three problems: it is a guide that gives you the right diameter and the right position before you even start the drill.

What is a drilling jig for?

It serves three complementary functions:

• Measure a diameter: by sliding a screw, wall plug or rod into the calibrated notches, you instantly identify its exact diameter — no more trying bit after bit.
• Choose the right bit: the matching guide hole tells you which bit to fit, including for pilot holes (a pilot hole slightly thinner than the screw prevents the wood from splitting).
• Position and guide the drilling: by holding the jig on the workpiece, you mark the exact spot with a pencil, then guide the tip of the bit without slipping.

The drilling guide built into Thorvald squares

On Thorvald 5-in-1 squares, the drilling jig is cut directly into the 4 mm aluminum: a series of calibrated holes from the thinnest to the widest, laser-engraved with their diameter. In practice, you measure, draw and mark your drill points with the same tool — without putting the square down.

Using it well: 3 tips

1. Mark before you drill: position the jig, mark the center with a fine-tipped carpenter pencil, then start at low speed.
2. Stay perpendicular: the jig gives you the position; keeping the drill square is up to you. On deep holes, check the angle against the side of the square.
3. Think pilot hole: in hardwood or near an edge, a pilot hole with a smaller diameter limits chipping and splitting.

Want to see the complete tool? Discover the 180 mm square with pencil, the 180 mm square alone or the 7-in-1 pack with the 300 mm Carpenter's Square.