Abstract: Stenter apparatus for stretching film comprises stenter frame clip chain assemblies adapted to grip opposite edges of the film. Each chain assembly includes a plurality of chain clip units (5) which are movable on a double track rail system (3, 4). Each clip unit (5) carries a series of rollers wherein rollers (10a, 10b) with a horizontal axis run on an edge of a track (4) for chain weight support while a plurality of vertical axis rollers (7a, 7b, 8, 9, 12) engage side surfaces of the track assembly to resist horizontal loading. A further roller (11) serves to prevent uplift of the chain assembly. The clip units (5) are linked by articulating link means comprising spaced link plates (21, 22) pivotally carried by link pins (23) in the clip units, each link pin additionally serving to support a drive roller (15). A film clip (6) is located on each chain clip unit (5) and above the articulating link means. Preferably the tracks (3, 4 ) are spaced vertically.