Quick Guide to Sergers and Overlock Machines

What are sergers (aka "overlock machine")?

Sergers are finishing machines that cut and finish the raw edges of the material (fabric) one is sewing. Unlike a straight-stitch sewing machine, sergers use loopers to make the stitch, and a set of knives (one on top that moves against the bottom blade) like a pair of scissors when cuting.

Sergers give garments a finished look in much less time than it would take with a regular sewing machine.

Shopping for a serger...

If you are looking for a serger -- as a first- time purchase or a replacement -- go to the store or online shopping site armed with knowledge on the subject! You'll be able to start narrowing down the field to find a serger that will make your sewing faster, neater, and more efficient.

Sergers, also called overlock machines, create professional factory-like stitches similar to those seen in ready-to-wear garments. If you know how to use a serger, they are huge time-savers because they let you sew about two to three times faster than standard sewing machines. Further, sergers can replace three operations with one step by sewing, cutting, and overcasting a seam all at once.

There are five types of serger machines:

  • 2-thread
  • 3-thread
  • 3-/4-thread
  • 4-thread
  • 5-thread

For best evaluation of how a serger will work for you, plan to test-sew the type of fabrics you use most often. It’s best bringing along some stretch knits as well as a variety of woven fabrics. Put together a set of representative swatches for each serger machine you want to try and use the Serger Evaluation Form (below). Sew (and label) samples, take notes, and then do your own comparison.

Serger Evaluation Form

Model name and number:______           Date:_______

For easy reference, you can attach the dealership's business card and any sewn samples.

Get to Know the Machine

  • Carefully inspect the serger, and find all the major controls, dials, and switches.
  • Flip the presser foot up and down.
  • Take note of the lighting. Does it allow you to see what you're sewing?
  • Listen to the machine and note its noise level and vibration as well as the type of surface it's sitting on.
  • Hold onto the thread chain and stitch without fabric.
  • Disengage and re-engage the upper knife.
  • Is a trim-catcher provided? Yes ___ No ___

Sew stitch samples: Test the following types of stitches, if available, and then label the samples.

  • 2-thread stitches: Overedge / Rolled hem
  • 3-thread stitches: Flatlock / Overlock / Rolled hem
  • 4-thread stitch: Overlock
  • 5-thread seam (overlock plus safety chain stitch)
  • Cover stitch

Ask dealers for demonstrations: Specifically, ask the salesperson to show you the following procedures, and try them yourself:

  • Engaging the differential feed (sew samples on stretch fabric and tightly woven fabric)
  • Chain- and /or cover-stitch conversion

Other stuff:

  • Is there any training offered with the purchase of the machine? If so, what type?
  • Machine maintenance: is this part of a packaged deal with the serger. If not, what type does the dealer recommend and provide?
  • Are there accessories available for this model? Sometimes, these may be found in the unit’s Owner’s Manual or literature. Also, the manufacturer’s web site may provide this information.

More info on Sergers: