Janome Top-Load - Hemmer Foot Set 4mm & 6mm The Hemmer Foot is used to stitch the narrow rolled hems usually found on shirt tails, table linens, and along the edges of frills. The hemmer is designed with a scroll shaped feed on top and a straight groove on the underside which determines the width of the finished hem. The 4 mm / 6 mm set will allows for the use of heavier fabrics.