in one longitudinal end edge to facilitate its bending into a position perpendicular to the base portion 11 similarly crease 40 can be formed at the opposite longitudinal end edge of the base portion 11 to facilitate the perpendicular positioning of tab 22 relative to the base portion 11 in operation a blank of material such as metal is stamped or otherwise formed in the configuration as seen in fig3 of the drawings in particular holes 21 are formed in tab sections 20 22 and creases 30 32 34 and 36 are formed to facilitate the bending of corresponding tabs 12 14 16 and 18 creases 38 and 40 may be formed to facilitate the bending of tabs 20 22 at one longitudinal end edge the tabs 12 20 and 14 are bent first along crease 38 the tabs 12 and 14 are then bent again about creases 30 32 in a similar manner at the opposite longitudinal end edge of the blank tabs 16 22 and 18 are bent along crease 40 tabs 16 and 18 further are bent along creases 34 and 36 to be positioned parallel to the base portion 11 the configuration of fig2 is then achieved slats may then be positioned so as to be embraced between the base portion 11 and tabs 12 14 16 and 18 the lugs 24 on each of these parallel tabs is then depressed inwardly to engage and perhaps to pierce the slats so embraced such clamps 10 are then positioned at two locations along each slat 8 the slats 8 are then arranged in parallel having the clamps 10 on each respective slat 8 arranged so.