Knives

Even before the stitches are made, the serger sewing machines' knives can trim the fabric! They contribute significantly to the tidy, polished appearance of your edges.  The majority of serger manufacturers follow the same design principles. You should try it out on a couple of pieces of test fabric before using it for your first sewing job. Continue to modify the sewing machine knives' blade width. Do this until you've found a setting that gives you the look you want.