Nail with extension above nail head - gives protection against marking from hammer heads

摘要

The nail has a head and a pointed shank which is provided with resistance to extraction. It has a disc-shaped head (1) which has an extension (5) on the opposite side to the shank (2) and co-axial to the shank. The diameter of the extension is smaller than the head of the nail. The ratio of diameters of the disc-shaped head and of the extension amount to 10:1 up to 2:1, whereby the extension exhibits sufficient blow strength. The diameter of the extension equals that of the shank. The height of the extension corresponds to at least its diameter up to twice its diameter.