Abstract: A connecting body for nails includes a large number of nails that are arrayed in parallel to each other at regular intervals, each including a shank portion welded to two wires respectively crossing the nails at two positions spaced apart from each other in a direction of an axial line of the shank portion so that the nails are connected to each other. A diameter of each of the two wires is set to be sufficiently smaller than a diameter of each of the nails. The shank portion of the each of the nails includes vertical ribs formed at a position of a welded portion on an outer periphery of the shank portion so as to protrude along the direction of the axial line of the shank portion. Outer surfaces of the two wires are welded to the vertical ribs of the nails.

Abstract: A fastener driving tool prevents the tool from twice striking, so-called double-driving in a single driving operation. A portion closing the lower end of a cylinder of the tool is formed with an annular recess to receive a ring bumper as a shock absorber of a piston. The recess has a sufficient depth to move a lower portion of the bumper downward and upward. The bumper is fittingly pressed into the recess to form an air chamber in the recess closed by the lower end of the bumper. A check valve is positioned between the air chamber and a supply of the pressurized air to feed the pressurized air to the air chamber so that the pressurized air is further compressed by the bumper which is downwardly moved by the abrupt downward movement of the piston. Thus, greater reaction force is applied from the air chamber to the lower portion of the bumper so as to prevent a driver of the tool from the double-driving.