<p>A dowelling jig for preparing aligned bores in corresponding joint faces of two work pieces which are to be joined using dowels, includes a spacer plate having opposite flat sides against which the side faces of the work pieces are placed and held. First and second drill guide arms are removable secured by securing arrangements to the spacer plate and to extend away therefrom in opposite directions, each arm providing a flat surface against which a joint surface of one of the work pieces is to abut. At least one line of through-bores are provided in each of the drill guide arms for guiding a drill bit at right angles into the work piece. The thickness of each guide arm is such that each through-bore has an axial length sufficient for guiding a hand held drill to drill a work piece bore substantially at right angles to the joint surface. The line extending along the guide arm parallel to an edge which abuts the spacer plate and the line of through bores on one arm corresponding in position to a through-bores on the other arm is such that the bores align when the joint faces of the work piece are brought into abutment.</p>
