Serging Machines are Seam Finishing Machines

Serging machines are finishing machines, sometimes called an overlock or merrow, and their function is to cut and finish the edge of the material to give the material a finished look. Unlike a straight stitch sewing machine, a serger uses loopers in order to make the stitch, and a set of knives- one on top that moves against the bottom blade- similar to a pair of scissors in action.

Sergers come in a number of different threads. A good example of a three thread serger is the Juki MO-623 Garnet Line Home Serger. A four-thread serger (like the Singer 14T948DS High Performance Overlock Sewing Machine) does the same stitch as the three-thread serger, but with an extra stitch going down the center for extra strength. The five-thread serger, (for example Juki MO-655 Pearl Line Home Serger), has a three thread overlock and an extra straight stitch. This is very good for heavier or woven materials, but not very effective on stretchy material because the straight stitch has no give.

Some five-thread machines now come with a coverlock stitch. This gives the effect of a double stitch on the top of the material and a closed zigzag on the bottom. It is very flexible and used on very fine garments. (Example: Singer 14T 957DC Serger)

Some manufacturers have now expanded up to eight threads on their sergers, but these machines do not give the consumer any more flexibility. Electronics and automatic threading systems can add greatly to the cost of the serger, but in the end, do not help the consumer.