The probe is the working part of the edge finder. It is connected to the shank of the tool by a tension-loaded spring.
When the probe makes contact with the edge of the part, the spring causes it to ‘jump out’ from the rest of the tool, indicating that the edge has been found.
The shank is the main body of the edge finder. When using the edge finder, it is important to note the diameter of the shank. This is because the diameter of the shank must be compensated for after the edge of a part is located.
The head of the edge finder is inserted into a collet or chuck which is then mounted onto the spindle of a milling machine or drill press.