Sewing Blog

Alternative to Serging: Lock Cutter Sewing Machine Attachment

Don’t have a serger in your sewing studio? This Singer Lock Cutter is a far less expensive alternative to serging. This simple device when attached to a regular sewing machine can sew and trim simultaneously much like a serger machine will do. It can be used to sew stitches much akin to serger stitches and finish seams in one step. Or, it can be used to trim and finish an already stitched seam.

Singer Lock Cutter Sewing Machine Attachment

For any sewer without a serger, this is a handy tool that fits a wide variety of sewing machine brands and models with a low shank presser foot arm. Like a serger, it can sew either an overcast or zigzag stitch while at the same time trimming away excess seam allowances. It creates a cleanly finished and evenly trimmed seam edge.

How to use the lock cutter sewing machine attachment

Step 1:

The device looks somewhat similar to a walking foot and attaches to the presser foot shank in the same way. Once the device is attached to the machine, set the stitch selector to either a simple overcast stitch for woven materials, or a zigzag stitch if sewing with knits. Set the stitch width to 5 mm or any desired width as long as it doesn’t hit the sides of the presser foot or the small finger in the center of the presser foot. The stitch length can be what you want it to be, but anything within 2.5 – 3 mm works best.

The markings on the front of the cutter gauge the width of the fabric to be trimmed away and are in millimeters. They help guide the fabric into the cutter so a straight cut and sew seam is achieved.

Using a Seam Gauge to Measure Fabric

Step 2:

Prepare the fabric for inserting into the device.  Make a 1 inch cut from the top edge into the fabric. The cut should be anywhere from 5 to 2 mm from the side edge of the fabric, or approximately ¼ – 1 inch. This represents the width of the fabric that will be trimmed away.

I prefer to use this device to trim and finish already stitched seams. So, if I have sewn a seam with a ⅝ inch seam allowance, I use the device to trim the allowance down to ⅜ inch, which means the width of my cut is ¼ inch from the edge.

Cutting with Lock Cutter Attachment
Sewing with Lock Cutter Attachment

Step 3:

Once the cut is made, the fabric is ready to be inserted into the device. With the presser foot and sewing machine needle in the raised position, slide the left cut of the fabric over the clear plastic bar into and then under the presser foot. The right cut of the fabric will also slide over the clear plastic bar, but to the right of the cutting blade. This will effectively separate the cut portions and clear the path for the cut and sew process to work.

Step 4:

With the fabric in place, lower the presser foot. Slowly — and I mean slowly — begin to sew, making sure the needle doesn’t hit either side of the presser foot or the center finger. Also, give those thread tails a bit of a pull to ensure the fabric doesn’t sink into the throat plate and the fabric progresses forward smoothly. Continue sewing at a slow, even pace.

Ok, so its not exactly a serger. But, it does a very good job of finishing seams so that the inside of your projects can look as good as the outside.

Fabric "serged" with lock cutter attachment

If you’d like to try your hand at using a serger, sign up for Craftsy’s class Beginner Serging: Machine Basics & Techniques with Amy Alan. You’ll gain confidence with using serger setup stitches while making three posh projects: an exposed zipper bag, an ombré ruffled apron and a striped knit scarf.

Do you use a lock cutter attachment?


Swiss Mrs

This looks very much like my Bernina Cut and Sew attachment (#80 with #90 presser foot).


Thank you for telling us about this. I once had a machine (Brother) with a foot like this, but didn’t know it could be purchased as an add-on. I have a serger but don’t always want to pull it out. This is great for small jobs.


Where do you get this attachment?????


where do you find these never seen it before?? will it work on other machines??


You have probably already found the answer to your question, but for the benefit of anyone else who reads this – Yes they do work with other brands of machine. I bought one for my Janome MC4800 and it works beautifully. Fitting it can be a bit fiddly initially but you soon get the hang of it, I found it easier remove the needle before fitting. The first time I used it it was rather noisy and clunky until I discovered that the thumbscrew that holds the needle in place was catching on the side of the cutter housing, probably because the thumbscrew is unnecessarily long on my machine. The solution was to file a little off the rounded end of the thumbscrew (the end that you hold, not the end that grips the needle) to stop it catching and now it works smoothly and quietly! I also find it easiest to thread the needle before I insert it in the machine. This might sound like a lot of hassle but it’s far simpler than threading up an overlocker. I can use all the edge finishing stitches on my machine in varying widths and lengths and the stitching is very flat and even and it cuts right up to the stitching, far closer than I could do with scissors. Please be aware that you can’t straight stitch with it – the needle will hit the presserfoot. I bought mine from Sewing Parts Online and I think it was well worth the investment.

Linda- Monkey Bizness

Wow that is really cool, ty for posting this! Gonna go google it now and see what sewing machine brands it will fit and see where I can purchase one on line.


will it work on my Husqvarna D2

BetyAnn Maki

Does it work with a Janome Horizon 7700? Thank you

gautham jain

interested to buy lock cutter from were we can get in india or hyderabad telangana



naeema T khopekar

I like this lock cutter where I can purchase in india

naeema T khopekar

I want singer zigzager attachment can I buy you send in india


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