How to Set the Cutting Blade on a Box Plane

Loosen the blade on your plane. Older, traditional plane blades are held in place with a wooden wedge -- modern planes are typically held in place with screws. Gently unscrew the screws just until the blade of the plane becomes loose. If your plane is a wooden wedge plane, tap the wedge lightly on the sides with a small hammer until both the wedge and the blade become loose.

Check the lateral alignment of the cutting blade. Turn the plane upside down and examine the area between the tip of the blade and the top of the throat (the window opening through which wood shavings pass). If the throat opening isn't even from side to side, gently tap the back end of the cutting blade with the hammer until the cutting edge comes into alignment.

Tap the back center of the cutting blade with the hammer until the cutting blade protrudes slightly below the base of the plane. Aim for a protrusion of only 1 or 2/100ths of an inch. Take care not to knock the blade out of alignment.

Tighten the screws or tap the back of the wedge to secure the cutting blade in place.

Plane a test piece of wood and examine the shaving. If the shaving is incomplete or if the plane only creates dust, loosen the cutting blade and tap the edge out another 100th of an inch.

Continue to plane and test until your planer produces very thin, consistent wood shavings. The shavings should be thin enough to easily bend but not so thin that they snap easily.

Hold the shaving up to a bright, focused light and examine it from the underside. The light should penetrate the shaving consistently across its width. If one side of the shaving appears darker, the wood is heavier in that area, indicating that the blade is slightly out of alignment. Loosen the blade and lightly tap the sides with a hammer to correct the imbalance.