Abstract: A hammer head assembly used in a power hammer for driving a nail into objects to be fastened is constructed to include a nail holder axially slidably mounted in a hollow mounting base and forced out of the bottom side of the mounting base by a spring member, a magnet fixedly provided inside the nail holder and adapted to attract a nail in vertical for driving into the workpiece, and a hammering rod axially inserted into the nail holder and controlled to drive a nail out of the nail holder into the workpiece.

Abstract: A hammer head assembly installed in an air nailing gun to guide a striking rod to drive a U-nail into a wooden material to fix a cord member to the wooden material is constructed to include a hollow mounting base fastened to the air nailing gun, a sliding sleeve moved in and out of the bottom end of the mounting base, a nail holder coupled to the bottom end of the sliding sleeve by a coupling nut and adapted to hold a U-nail in a flat receiving slot thereof for fastening, magnets mounted in the nail holder for securing the loaded U-nail in position for driving, and a hammer rod supported on a spring inside the sliding sleeve for driving by the striking rod of the air nailing gun to force the loaded U-nail out of the nail holder into the wooden material to fix a cord member to the wooden material.

Abstract: A portable punching machine includes a pneumatic cylinder controlled to reciprocate a piston rod, and a punching mechanism coupled driven by the piston rod to punch holes on a metal workpiece, the punching mechanism including a locating block fixedly fastened to the pneumatic cylinder, the locating block having a plurality of bottom notches and a center through hole adapted to receive the piston rod of the pneumatic cylinder, an actuating block and adapted to move the workpiece relative to the locating block upon movement of the piston rod, the actuating block having a plurality of peripheral side notches selectively coupled to the metal workpiece, and pairs of guide holes aligned at two sides of the peripheral side notches, and a plurality of punching tool assemblies adapted to make holes on the metal workpiece, each punching tool assembly including a barrel mounted in one guide hole of the actuating block, a set of spring washers mounted in one bottom notch of the locating block, a punching rod mounted in o