An awl, also known as a scratching awl, is a hardened steel rod sharpened to a point. Most awls have a wooden or plastic handle. They are used for scribing lines to be followed by a handsaw or chisel; for punching holes in soft materials such as leather or vinyl; and to make small holes in wood for starting nails, drill bits, and screws. An awl is generally used when dimensioning and for laying out with the grain; a marking knife works better for marking across the grain. An alternative to the awl is a metal scriber.
When buying an awl, look for one that fits comfortably in your hand and check that the shaft tapers evenly to a sharp point.