Abstract: A universal hammer having separable handle and head portions to permit the use of interchangeable heads. The head is formed with a female threaded bore which threadedly engages a male threaded shank. A cross hole is formed through both the head and the shank so that a pin may be inserted to retain the separable parts against relative rotation. A collar is also threaded to the shank and has a cylindrical portion which surrounds the cross bore to prevent removal or loss of the pin. A locking nut jams against the collar to prevent it from becoming loose.