This Marking Knife is a precision tool designed for marking and scribing on wood, metal, and other materials. It features a sharp, pointed blade that is perfect for making precise lines and marks. The ergonomic handle ensures a comfortable grip and the blade is made of high-quality steel
From Wikipedia
A marking knife or striking knife is a woodworking layout tool used for accurately marking workpieces. 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. They are generally used when marking across the grain of the wood, with scratch awls better suited for marking with the grain.