A one-step buttonhole is sewn in a single continuous operation at a size the machine measures. A four-step buttonhole is sewn in four passes, with you changing the setting between each one.
One-step. The foot generally has a slot at the back where you place the actual button. The machine reads that length, then sews the first bar tack, one side, the second bar tack, the other side, and stops. The real benefit is not speed — it is that every buttonhole on the garment is exactly the same length, which is what makes a row of them look right.
Four-step. You sew one side, stop, change the dial, sew the bar tack, change again for the second side, change again for the final tack. It makes a perfectly good buttonhole. What it does not do is guarantee consistency: unless you count stitches or mark the fabric at both ends, the lengths drift and a row of buttonholes on a shirt front shows it.
Older and vintage machines often have four-step, or a bolt-on buttonhole attachment driven by metal templates. Those attachments make excellent, very consistent buttonholes and are worth having if one comes with a machine.
Whichever you have, the preparation is the same. Interface the area — a buttonhole in unsupported fabric stretches and frays. Sew a full test on the exact layers you will use, including interfacing. Cut with a buttonhole chisel if you have one, and put a pin across each end so the blade cannot run past the bar tack.
Test the buttonhole mechanism before buying any used machine. It is a common failure and an expensive one.
Questions people actually ask
Can I make a buttonhole without either?
Yes — set a narrow satin stitch, sew the two sides and the two ends manually, and pivot at the corners. It is slower and needs marking, but it works on any zigzag machine.
Why does my one-step buttonhole come out different lengths?
Usually the fabric is not feeding evenly under the buttonhole foot. Interface it, use a stabiliser, and let the machine feed without helping it along.
Last reviewed 2026-08-11