A winding mat formed as a flat winding and to coil mat formed from it for producing a coil winding for an electric machine. To be able to manufacture different coil mats also with layer swap and conductor swap in an automated manner and in large series and with a high degree of reliability, it is proposed to join wave winding wires by plugging. To produce the coil mat, it is proposed, among other things, to join two individual mats by plugging the mats together.