A clip is disclosed which can be used to fabricate the lattice structure of reinforcing rods of the type used in the construction of steel rod reinforced concrete slabs. An apparatus to fasten those clips in position is also disclosed. The preferred clip (1) has a substantially rectangular body (2). A recess (3) extends from a first face (4) of the body (2) towards an opposite face (5). The recess (3) terminates in an arcuate portion (6). The inner edges (7a, b) of the recess (3) are convergent towards the arcuate portion (6). The apparatus has an aperture (13) in a base plate (12). Stops (18a, b, c) on the plate (12) suitably position the apparatus whereupon a shearing plate (32) can shear a clip (1) from a stack of such clips to pass through the aperture (13) wherein the arcuate portion (6) of the clip (1) engages the upper rod (16). A pair of pivoting J-shaped arms (21a, b) are then actuated which bend the lower portions of the clip (1) around the lower rod (17) securing the two rods (16, 17) together.