Abstract: A fastener for securing built-up roofing membranes used to waterproof cementitious roof decks combines the conventional nail used for this purpose having a head and a shank portion designed to resist withdrawal of the fastener from the deck, with a non-integral tab penetrated by the shank of the nail and of larger diameter than the nail head, the tab having a design which allows the fluid asphalt conventionally poured over the nail during construction of the roofing membrane to bond the portion of the membrane beneath the tab and thereby increase the wind uplift resistance of the covering material. Removability of the tab allows its detachment in applications where increased uplift resistance is unnecessary.

Abstract: A clinch type nail having a generally flat shank with a pair of spaced penetrating portions having inner and outer walls that are disposed in angular relationship with each other and intersect along a generally straight line. The outer walls offer more resistance to penetration than the inner walls when the nail is driven which causes the penetrating portions to clinch inwardly toward each other and capture a plug of the material into which the nail is driven.

Abstract: A fastener having an integral head and shank which are formed from a strip of sheet metal of indeterminate length in which the head is formed by slitting and compressing a section from one edge of the sheet material to provide a split head having two substantially similar halves with at least a portion of each half being generally perpendicular to the shank and with at least a portion of the head being thicker than one-half of the thickness of the sheet material and in which the forming of the head causes a slot in the upper surface of the head which is less than one-third the thickness of the sheet material.

Abstract: A sheet metal nail of the type used to fasten a covering material to a lightweight base material in which a pair of interfitting generally U-shaped legs are connected to an enlarged head and such legs have means for spreading the legs apart when driven and means for locking the legs in spread apart condition.

Abstract: A nail or fastener including a shank having a hollow penetrating portion with a continuous circular blunt end of predetermined width which can be driven into a relatively thick structural metallic member. The penetrating portion of the nail is of a configuration and hardness such that the circular blunt end crimps inwardly to capture a plug of material within the hollow penetrating portion and such plug of material remains joined to the metallic member so as to resist withdrawal of the nail.

Abstract: A fastener apparatus which can be formed by conventional punch press machinery and which is hardened so that the fastener may be driven into metallic structures such as structural steel beams and the like using a conventional hammer or a power operated nailing gun. The apparatus includes a flat body having a penetrating head at one end connected to the body by a reduced neck and such penetrating head is smaller in width than the width of the body. The portion of the body adjacent to the neck is provided with an overlying ledge which forces material into the area adjacent to the neck to form a mechanical lock which resists withdrawal and prevents rotation of the fastener within the material.

Abstract: A sheet metal nail of the type used to fasten a first or covering material to a lightweight base material in which a pair of interfitted channel shaped leg or shank members are pivotally connected to the nail head in a manner to spread outwardly into the base material when the nail is driven therein. The penetrating ends of the shank members are tapered to form cutting edges so that as the nail is driven, the penetrating ends of the shank members cut through the first material without tearing such material.

Abstract: A fastener apparatus having an elongated body with a hardened substantially non-bendable penetrating portion at one end which can be driven to a predetermined depth in metallic structures by a fluid or electrically operated driver or by a manually operated hammer and which forms a mechanical lock with the metallic structure to resist twisting, bending and extraction therefrom.

Abstract: Fastener apparatus for securing lightweight insulating material onto sheet metal without passing entirely through such sheet metal. The apparatus includes a clinch type fastener having a penetrating end with means to provide limited penetration of relatively thin sheet metal and to clinch portions thereof to attach the fastener to the sheet metal and to prevent ready withdrawal of the fastener.