Ippon-zao Suji-Keshiki -

ONE BEAM Marking Gouge TAKAKATSU

Japanese marking gauges are equipped with knives instead of needles and feature a relatively wide fence. These small knives have the advantage of being able to score cleanly even across the grain. Knives cut the fibers, whereas needles only tear them. Like other Japanese woodworking tools, this one is also used by pulling.

The blade of the Keshiki is ground on one side, with the bevel facing inward, so the cutting edge is turned away from the fence. In Kama-Keshiki (tenon marking gauges) with two knives, the bevels face each other, while in Suji-Keshiki with two wooden tongues, the bevels are parallel and not facing each other. If, in its delivered state, the cutting edge does not protrude enough from the slot, you should never try to drive the knife in with strong hammer blows, as the wood of the tongue could split. Instead, gently enlarge the slot with a needle file or a sharp knife. It is sufficient if the knife edge protrudes 1 – 5 mm, depending on personal preference. However, it should not be more than that, as otherwise, you won’t be able to hold the marking gauge exactly horizontally over the workpiece. Then press the knife in and secure it with only very light hammer taps!

The printed scale should only be seen as a guide, and the distance from the knife edge to the fence should always be checked with a ruler. Fine adjustments can be made on Keshiki with a wedge by carefully tapping the broad side of the hammer on the respective ends (end grain) of the tongue. The wedge can be secured with firm thumb pressure or, if that is not sufficient, with a light hammer tap.

The fence on this marking gauge is held by a thumbscrew.
This is not entirely traditional, but it greatly facilitates setting it up and working with it.