Differential feed means the overlocker has two sets of feed dogs that can move at different speeds relative to each other.
The front set feeds fabric in; the back set takes it away. When they run at the same rate, the fabric passes through unchanged. When they differ, the fabric is deliberately stretched or compressed as it is sewn.
Setting above 1.0 — the front feeds faster than the back, so fabric is pushed in and slightly compressed. This is what stops knits waving. It is the correct setting for jersey, and typically somewhere between 1.2 and 1.5.
Setting below 1.0 — the front feeds slower, so the fabric is stretched as it passes. Used for lettuce-edge hems, and to stop lightweight woven fabric puckering.
Setting at 1.0 — neutral. Normal for stable wovens.
How to find the right number. Sew a test strip of the actual fabric at 1.0 and look at the edge. Wavy means increase it. Puckered means decrease it. Adjust, test again, and write the number down for that fabric — you will use it again.
It is the single most useful control on an overlocker and the one most owners never touch, because it is not obvious what it does from the dial.
Questions people actually ask
My overlocker has no differential feed.
Then reduce presser foot pressure if you can, and support the fabric so it is not dragging. You can also hold the fabric very gently behind the foot to stop it stretching.
Can I use it to gather?
At the maximum setting on lightweight fabric, yes — it produces a light gather. It is not a substitute for proper gathering on anything substantial.
Last reviewed 2026-08-11