A device for automatically securing a borderwire on a mattress innerspring comprising a plurality of coils is disclosed. The device comprises a tool for sequentially joining segments of the borderwire to perimeter ones of the coils located along a perimeter of the innerspring, apparatus for advancing the mattress innerspring and borderwire toward the tool, a conductive element for sequentially contacting the perimeter ones of the coils, a sensor for detecting contact of the conductive element with the perimeter ones of the coils, and a control responsive to the sensor for actuating the tool.