The fundamental precision layout tool is the height gage. The vernier height gage is the most common type found in the machine shop. This instrument will discriminate to .001 in. With this ability, a much higher degree of accuracy and reliability is added to a layout task. Whenever posible, you should apply the height gage in all precision layout requirements. Major parts of the height gage include the base, beam, vernier slide, and scriber. The size of height gages is measured by the maximum height gaging ability of the instrument. Height gages range from 10 to 72 in.