A test device includes a base rested on an object, an inserting member slidably mounted to the base and contacts a slanted surface of a chamfer of the object, and a test member slidably rested on the base. The base includes a positioning bar abutting a bottom end of the chamfer. A first cutout and a second cutout communicating with the first cutout and positioned in front of the first cutout are defined in a bottom surface of the testing member. A depth of the second cutout equals the tolerance of a standard depth of the chamfer. If a top surface of the inserting member can be received in the second cutout, the depth of the chamfer is qualified. If the top surface of the inserting member cannot be received in the second cutout, the depth of the chamfer is unqualified.