PURPOSE: To ensure the connection and holding of nails by providing irregularities in an engaging position.

CONSTITUTION: Each of connected nails 1 is nipped by tabs 3 formed by bending both side edge parts of a plastic sheet (connecting member) 2, and connected in parallel on the plastic sheet 2. The connected nail 1 is formed of a disc nail head part 5 and a nail shaft part 6 extending from the center of the head part 5, and a circumferentially extending locking groove 7 is provided on the circumferential surface of the nail shaft part 6 over the axial direction substantially at equal intervals. The connected nail 1 is prevented from being slid in the axial or circumferential direction by vibration and dropped out from the plastic sheet 2 by engaging the locking hole periphery 16 with the locking groove 7. Even when the locking hole periphery 16 is not engaged with the locking groove 7 at the point of time when the connected nail 1 is formed, the locking hole periphery 16 is engaged with the engaging groove 7 at the point of time when the nail starts to slide, and the slippage is prevented. The locking groove 7 provided on the nail circumferential surface increases the pulling resistance when the nail is driven into a plate to perform a stronger connection.