Block plane
A block plane is the smallest of the common bench planes, a hand tool that pares and smooths wood by pushing a blade across it, sized to work comfortably in one hand for trimming, fitting and finishing small work.
Size and build
A block plane is typically between about three and a quarter and seven and a quarter inches long. Unlike most bench planes, its blade sits in the body bevel-up, meaning the sharpened angled face points upward, rather than bevel-down. Because a block plane cuts across the grain, the direction that runs across a board's fibres rather than along them, it needs no cap iron, the extra blade fitted above the main iron on most planes to curl and break up shavings. Audels (1923) traces the plane's name to this kind of work: "this latter work many carpenters call 'blocking in,' hence the name block plane."
Materials and types
A block plane can be made of wood or metal. In the Japanese woodworking tradition, Nakashima (1981) considers a wooden block plane made of kashi, a dense oak used for plane bodies, ideal for fine work. A rabbeting-style block plane, one variant, has its mouth, the opening in the sole through which the blade projects, open on both sides of the sole rather than only in the middle. An edge can also be trimmed with a low-angle block plane, one ground with a shallower blade angle, or with a file.
Using it
A block plane cuts better when it is skewed, angled slightly sideways rather than pushed straight, as it is worked forward. A larger block plane can smooth and trim even the toughest end grain, the surface left where wood is cut across its fibres. Alongside files and cabinet scrapers, thin steel blades that shave off fine curls of wood when scraped across it, a block plane can produce very accurate surface finishes. Rounded profiles can be shaped first with a sharp block plane and then smoothed with a sanding block, and a nosing profile, the rounded front edge of a stair tread or similar moulding, can be continued around a piece's ends with a block plane before it is finished with abrasive paper.
Fitting and small work
A block plane can trim small fitted parts, called keys, until they fit properly, with the strokes worked outward, away from the corners, as the piece is finished. A spline, a thin strip of wood glued into matching grooves to help align and strengthen a joint, can usually be cleaned up with just a few block-plane passes once it is already close to its finished length. After a mitre, a corner joint cut at an angle so two pieces meet without showing end grain, is cut, a block plane may be used to fit it before it is temporarily nailed in place. Short and heavy, and made of either wood or metal, a block plane pairs with a mitre-shooting jig, a guide that holds a mitred piece steady while the plane trues its cut, and a suitable block plane must be used carefully in this work to avoid marring the surface of the pieces being trimmed. A block plane, or a sanding block, can also trim a binding shoulder slightly to fix a tight fit, and it can chamfer a shop jig's edges, cutting a small flat bevel along a sharp corner, to remove the risk of splinters. In timber-frame pendant finishing, a pendant being a hanging decorative drop worked into a frame member, a block plane follows paring with a slick, a large chisel-like tool pushed with both hands, and a chisel to finish beveled cuts.
Limits
Nakashima (1981) finds that even highly skilled hands using a wooden block plane can rarely avoid small tear-out, torn or lifted grain left by the cutting edge, when finishing rippled or burled walnut figure, walnut with an unusually wavy or knotted grain pattern.