A nail having an elongate shank, a head at one end of the shank and a tip portion at the other end. A lateral step is formed in the shank at a location spaced from both the head and the tip so as to divide the shank into a relatively small diameter penetrating portion which is adjacent the tip, and a relatively large diameter gripping portion which is adjacent the head. Any of a variety of gripping features, such as ribs or teeth, could be provided on the gripping portion to assist its grip within a member to which the nail is to be secured.

A screw of the self-drilling and self-tapping kind intended to be used in fastening corrugated or similar cladding to a support structure is disclosed. The screw shank is provided with a feature, such as, for example, a circumferential series of axially extending ribs, which is operable to enlarge (such as, for example, by means of a reaming process) a hole formed through the cladding by means of the drilling tip of the screw. The hole enlarging feature is positioned at or adjacent to the junction defined between a threaded section of the shank and a non-threaded section which extends from the screw head. The hole enlarging feature is arranged so as to ensure that the aforementioned hole, as enlarged, has a diameter which is not less than that of the non-threaded section of the shank. There is also disclosed a method of forming such a screw in which the thread is formed by means of a thread rolling operation, and the thread rolling die is modified so as to automatically produce the hole enlarging feature upon the screw shank during the course of the thread rolling operation.