This precision flat machinist square is made by Kinex Measuring who has been in the business of making precision measuring tool since 1906. This square is perfect for the professional machinist, meticulous wood worker, or the DIY perfectionist. It is machined from one solid steel blank, and will never go out of square. The faces have a milled finish, while the reference edges are lapped for straightness and parallelism. Manufactured to strict German DIN 875/1 standards and guaranteed square to within 15 microns or 0.0005 inches over the entire length of the longest edge (that’s just half a thousandth). Comes in a padded box. Includes signed inspection certificate.