A test device for testing whether an axis of a first portion of an article is coaxial with an axis of a second portion of the article includes a supporting member, a benchmark member fixed to a first end of the support member, and a test member slidably received in a second end of the supporting member opposite to the first end. The benchmark member includes a first test portion to position the first portion of the article that are coaxial within a coaxial tolerance. The test member includes a second test member coaxial with the first test portion. If the second portion is capable of being positioned to the second test portion, the article is qualified. If the second portion is incapable positioned to the second test portion, the article is unqualified.