A chewed rather than cut edge is a blade problem in most cases, and no amount of tension adjustment will hide it.
Check the cutting width first. If the blade is barely skimming the edge, it is dragging fibres rather than cutting them, and the stitch has too little fabric to hold. Increase the cutting width so a consistent strip is being removed. This is the commonest cause and it is a dial, not a repair.
Check the blade is engaged and clean. Trimmed fibre and fusible adhesive build up in the cutting area and stop the blades meeting. Clean it before assuming anything is worn.
Check the blade condition and alignment. Blunt blades chew. So do blades that have drifted out of their specified overlap. On most machines the lower moving blade is the wearing part.
Then look at the fabric. Very loose weaves, open knits and anything fraying badly will always look rough at the edge. On those, cut wider and let the machine trim more, or stabilise the edge first.
Then differential feed. Set for stretching rather than easing, it pulls the edge as it cuts, which distorts the cut line on knits and produces a ragged appearance that looks like a blade fault.
Then presser foot pressure. Too low, the fabric lifts and moves under the blade instead of being cut cleanly.
Then the stitch width. Too narrow on fraying fabric and the fibres simply pull out from under the stitching.
Test on a doubled woven scrap. A clean cut there with a chewed edge on your project fabric means the fabric is the variable, not the machine.
Questions people actually ask
It only happens on knits.
Check differential feed and presser foot pressure first. Knits stretch under the blade, and easing them slightly gives a much cleaner cut line.
The fabric is being pulled into the machine.
Fine and lightweight fabric does this. Reduce pressure, hold the fabric taut without stretching, and consider a wider cutting width so there is more to grip.
Last reviewed 2026-08-11