What Is A Spur?

Various (but not all) multi planes, combination planes, plough ( plow) planes and rebate planes are equipped with a spur.

A spur is a small metal piece, usually circular with a sharp point / edge protruding from it which when in use usually sits near the bottom or the plane at some point in front of the plane blade, with the point of the spur pointing below the line of the plane sole.

What is the spur for? What is the purpose of the spur?

The purpose of the spur is to help produce a good cut by preventing tear-out and splintering of the timber on cross-grain work.

How does the spur work?

As the plane is pushed along the wood, the spur scores / slices the wood just before the plane blade shaves the wood. The slicing / nicking of the wood alters the structure of the surface in a positive way which enables the main plane blade to make an effective smooth cut.

How to sharpen a spur?

The spur(s) should be kept sharp to ensure they function correctly.

The cutter edge of the spur has a bevel. This bevel is the part which needs to be sharpened to produce / maintain a sharp edge.

The spur is very small so it can be a little fiddly sharpening the spur.

One good way of sharpening the spur is by holding the spur with flat-nose pliers on a work surface and then honing the bevel side with either a slip stone or a small smooth file.

The opposite smooth side may build up a few burs / small metal filings which should be removed by lightly running the slip stone over it. Care should be taken not to form a bevel on the smooth side when removing any burring.

YOUTUBE VIDEO: How to sharpen a spur?