Abstract: Stenter apparatus for stretching a web to produce a relatively thin film comprises two transversely spaced endless chains one the mirror image of the other relative to the stenter center line (C--C), each chain comprising an inner feed run (9) and an outer return run (10) mounted on supports. Each endless chain is constituted by film clip holders (3) and the chain pases around end sprockets (11B, 12B). The present invention provides a means for lateral adjustment of the feed runs (9) comprising adjustment means for lateral movement of the feed run support relative to the return run support and pivoting portions (10A, 10B) in the outer run support adjacent the end sprockets (11B, 12B) to enable said lateral movement of the feed run. Consequently a major portion of the outer run support does not require to have lateral movement and can be fixed in position and this provides economies in the construction. Further, end sprockets (11B, 12B) of smaller diameter can be used.