Connecting piece for connecting poles of two batteries or battery cells, and production method for a connecting piece for connecting poles of two batteries or battery cells

Connecting piece comprising a stamped metal sheet for conductively connecting poles of two batteries or battery cells, which connecting piece has a main body (1) with a recess, wherein at least one insert element (6) is arranged in the inner region of at least one recess. Either the insert elements (6) have a groove on the circumferential face thereof, said groove running at least in regions of the circumference, or the main body has a groove (8) on the inner face of the at least one recess therein, said groove running at least in regions of the circumference. The respectively corresponding component has a projection which is generated by material displacement when the two or one of the two components are/is pressed and which engages in the groove (8) in an interlocking manner, so that the main body (1) and each insert element (6) are connected to one another, in an interlocking manner at least in regions, along the circumference of the insert element (6).