nail plates

A truss connector plate is a kind of tie. Truss Plates are light gauge metal plates used to connect prefabricated light frame wood trusses. They are produced by punching light gauge galvanized steel in order to have teeth on one side. The teeth will allow to join different trusses together by being embedded into the lumber using an hydraulic press or a roller.
A truss connector plate is manufactured from ASTM A653/A653M, A591, A792/A792M, or A167 structural quality steel and is protected with zinc or zinc-aluminum alloy coatings or their stainless steel equivalent. Metal connector plates have integral teeth and are manufactured to various sizes (that is, length and width) and thickness or gauges and are designed to laterally transmit loads in wood. They are also known as stud ties, metal connector plates, mending plates, or nail plates. However, not all types of nail plates are approved for use in trusses and other structurally critical placements.
Nail plates are used to connect timber of the same thickness in the same plane. When used on trusses, they are pressed into the side of the timber using special hydraulic tools. As the plate is pressed in, the nails are all "driven" simultaneously and the compression between adjacent nails reduces the tendency to split.