What is a compass saw?
A compass saw, also called a keyhole saw (Dutch: schrobzaag), is a hand saw with a narrow, tapering blade on a pistol or straight handle. Thanks to its pointed tip you can start cutting in the middle of a board and make tight curves. The compass saw is therefore intended for cutting holes, rounded shapes, curves and cut-outs in timber, sheet materials and plastic.
Compass saws come with different blades. A thicker, coarser blade cuts quickly through timber and plasterboard but is less suitable for plastic or precise work; a thin, fine blade makes tighter curves and a cleaner cut. The powered equivalents are the jigsaw and, for rough work, the reciprocating saw, which can be seen as a powered compass saw.
Application
Typical jobs:
- cut-outs for back boxes, downlights and pipes in plasterboard or sheet material;
- an opening for a hatch, grille or drain in an existing wall or floor;
- curves and bends where an ordinary hand saw cannot reach;
- short cuts in awkward places.
Tips:
- Starting in a board: with plasterboard you can push the tip through with a few taps or by pressing. With timber or thicker sheet material, first drill a hole slightly wider than the blade in a corner of the cut-out.
- Mark out and check behind the board: check (with a cable and pipe detector) that there are no pipes or cables behind it before you cut.
- For round holes of a fixed size (such as back boxes or downlights) a hole saw in a drill is quicker and neater.
- Let the saw do the work: use the full length of the blade and do not press too hard; a narrow blade bends and kinks easily.
- Prevent splintering: on delicate finishes, apply masking tape over the cutting line and cut from the face side.
Related Terms
- Reciprocating saw
- Hole saw
- Plasterboard
- Wood species
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