Apparatus for laser welding a first metal part (1) to a second metal part (2), which apparatus comprises: a laser (3) which emits a laser beam (6) in the form of laser pulses (21), a scanner (4) for moving the laser beam (6) with respect to a metal surface (7) of the first metal part (1), an objective lens (5) which focuses the laser beam (6) onto the metal surface (7), and a controller (12) which controls the scanner (4) such that it moves the laser beam (6) with respect to the metal surface (7) to a plurality of focussed spots (16), characterised in that the apparatus focuses the laser pulses (21) with a spot size (34) and a pulse fluence (36) that causes the formation of a plurality of melt pools (19) in the first metal part (1) and heat stakes (17) in the second metal part (2), each heat stake (17) extends from a different one of the melt pools (19) and has a distal end (101), and the controller (12) spaces the focussed spots (16) apart by a distance (18) that is small enough to cause the melt pools (19) to overlap and that is large enough to ensure the distal ends (101) of the heat stakes (17) are distinct and separate from each other in at least one direction (108).