| Marking knife | |
| Image Size: | 240 |
| Used With: | Straightedges, squares, scratch awls, pencils |
A marking knife or striking knife is a woodworking layout tool used for accurately marking workpieces.[1] It is used to cut a visible line, which can then be used to guide a hand saw, chisel or plane when making woodworking joints and other operations.[2] They are generally used when marking across the grain of the wood, with scratch awls better suited for marking with the grain.[3]
The blades on marking knives are made of tool steel, have either a skewed end or a spear point, and the knife edge is bevelled on either one side of the blade or both sides.[4] On single-bevel skewed knives the side of the blade that is bevelled dictates whether the knife is for left-handed or right-handed use, while single-bevel spear point knives are suited to both.[5]
Some marking knives incorporate a marking knife blade at one end, and a scratch awl tip at the other end – but because of this they are sometimes considered dangerous to use.
Marking knives are either made from a single piece of steel, or additionally have a handle made of wood or plastic.
Some woodworkers make their own marking knives, for example from spade bits or planer blades.[6] [7]
Marking knives are usually held like a pencil, and are guided using a straightedge or square. Sometimes woodworkers will gently run a sharp pencil along the line afterwards to make it more visible.
Marking knives are sharpened in a similar manner to chisels or other bladed tools – using sharpening stones, files or sandpaper.
A shirabiki is a Japanese marking knife made from a single piece of steel with a skewed single-bevel blade.
A double-bladed shirabiki is used for marking parallel lines. They are made with two parallel blades and a thumbscrew for adjusting the distance between the blades.[8]