By employing a deadbolt construction for virtually eliminating the ability of the shackle to be removed from the housing by the application of excessive force, an effective, easily produced, padlock is achieved which also incorporates two separate and independent locking systems formed in a single padlock. In the present invention, a single housing and a single shackle assembly are employed and are constructed for enabling the shackle to be released from locked engagement with the housing using either a rotatable dial combination construction or a key activated tumbler construction. Furthermore, the rotatable combination defining dials, which controls the release of the shackle using the preset combination, are coaxially aligned, peripherally surrounding the key controlled tumbler / cylinder. As a result, a compact construction is realized, as well as an efficient and effective release construction which is shared by both the combination controlled section as well as the key controlled section.