Check the tool path of your CNC machine with the highest degree of precision. These calibration squares can lay flat to check that the X- and Y-axes of your tool path are at 90°. Or sit them up vertically to confirm the Z-axis is perpendicular. Made of Laboratory Grade AA granite, these squares have the tightest flatness tolerance available for granite. They also come with a calibration certificate traceable to NIST that states they've passed a test for accuracy. Moisture, coolant, and chips won't affect the granite, so they remain accurate even when used inside a milling machine. You can also use them to check the squareness and parallelism of finished workpieces.

They have drilled holes to reduce their weight and make them easy to position.

Tri-square plates have a face and two edges for checking 3-axis machines.

Square plates have two additional edges for checking both 3-axis and 5-axis machines.

For technical drawings and 3-D models, click on a part number.