Abstract: Method for applying an electrical contact to a hole (2) of a metal wall portion (1), comprising the steps of providing a bush (12), a punch (11) with a shaft (16), an expansion portion (19) and a connecting portion (20) thereof, a pulling device (21) with an abutment portion (22) and a pulling mechanism (23) for engaging the punch (11) and to pulling it proximally with respect to the abutment portion (22), inserting the punch (11) in a passage hole (25) of the bush (12) so that the connecting portion (20) protrudes proximally from the bush and the expansion portion (19) is located on end (14), bush connecting the punch (11) to the pulling device (21), inserting the preassembled bush (12)-punch (11)-unit from a proximal side of the wall portion (1) distally in the hole (2) and activating the pulling device (21) to pull the punch (11) proximally through the bush, thereby radially expanding bush and permanently anchoring it in the hole (2).