When you buy through links on this site, I may earn an affiliate commission at no extra cost to you. Learn more.

Three-Thread Overlock vs. Four-Thread Overlock – What Is The Difference

Because it contains one needle and two loopers threads, the three-thread overlock is best for overcasting seams and finishing raw edges of woven textiles.

The four-thread overlock, which contains two needles and two loopers threads, maybe a better alternative if you want stronger and sturdier seams.

Because I mostly work with lightweight to medium weight fabrics and locally made textiles, I utilize three-thread overlock 90% of the time.

The most popular and sought-after overlocks are three-thread and four-thread overlockers. They are similar in their applications, yet they have certain distinguishing qualities.

Here’s how to tell the difference between a three-thread overlock and a four-thread overlock.

What Is the Definition of a Three-Thread Overlock?

One needle thread and two loopers threads are used to make a three-thread overlock stitch. This stitch is most commonly used for stitching knitted materials.

You may sew woven materials with this stitch, but not stress areas like the crotch of pants or the sleeves of shirts.

Depending on which side of the needle is used when sewing, the stitch might be narrow or broad.

You can utilize either needle side of the overlocking machine because only one needle thread is needed in a three-thread overlock.

Like every other overlocking method or machine, the three-thread overlock was invented in 1889 by Joseph Merrow, who also invented the overlock machine.

The entire evolution of the three-thread overlock occurred over the nineteenth and twentieth centuries.

The three-thread overlock is a popular product worldwide, but notably in the United States, Europe, and Australia.

It is mostly produced in the United States and Asia, particularly China, Japan, and India, and transported to nearly every country on the planet.

It is one of the most often used overlock stitches. The three-thread overlock stitch is ideal for knitted and woven materials that will not be subjected to significant wear and tear.

A three-thread overlock can be used to complete or create ornamental stitches. Patchwork piecing, blind stitching, piping, and adding lace, trimmings, or beads to textiles are all possibilities.

What Are the Benefits of Three-Thread Overlocking?

Three-Thread Overlock Is Extremely Versatile and Long-Lasting

The three-thread overlock stitch is more flexible and robust than the two-thread overlock stitch. Stitching may go through various materials, especially those that aren’t subjected to a lot of wear and tear.

Because it only utilizes one needle, the three-thread overlock is more flexible than the four-thread overlock, resulting in fewer bulky seams.

What Are the Drawbacks of Three-Thread Overlocking?

It isn’t easy to work with a 3-thread overlock

On heavy-weight fabrics, using a three-thread overlock might be difficult because the edges may not wrap properly. As a result, it may be difficult to work with on canvas, corduroy, or denim.

Using a three-thread overlock may result in overlapping regions, necessitating a stronger needle while stitching.

Not All Fabrics Are Suitable for Three-Thread Overlock

While the three-thread overlock is versatile and long-lasting, it isn’t always appropriate for heavier fabrics.

The three-thread overlock lacks a second needle thread that would have given stability during stitching, and these materials demand a strong needle to get through them.

What Is the Definition of a Four-Thread Overlock?

Two-needle threads and two loopers threads are used to make a four-thread overlock stitch. It is the strongest construction stitch because it creates seams for a wide range of knitted and woven textiles.

It’s particularly well-suited to medium- and heavy-weight fabrics. Due to the two needle threads sewing, the four-thread overlock provides a larger stitch. Needle stitching creates thicker and more thick seams.

The four-thread overlock is a popular product worldwide, but notably in the United States, Europe, and Australia. It is mostly produced in the United States and Asia, particularly China, Japan, and India, and transported to nearly every country on the planet.

Like every other overlocking method or machine, the four-thread overlock was invented in 1889 by Joseph Merrow, who also invented the overlock machine. The entire evolution of the four-thread overlock occurred over the nineteenth and twentieth centuries.

The most common overlock stitch is the four-thread overlock. It’s used to sew elastic into clothing and to put zippers in them. It assists in fabric gathering and is best utilized in high-stress places such as the crotch of pants or the sleeves of shirts.

What Are the Benefits of Four-Thread Overlocking?

The four-thread overlock is extremely strong and long-lasting.

Because it employs two needles, the four-thread overlock gives strength to the cloth being stitched. The second needle thread strengthens the looper threads and helps to wrap the edges neatly.

Because the seams are thicker and can endure wear and tear, it is also highly durable.

What Are the Drawbacks of Four-Thread Overlocking?

It isn’t easy to work with a 4-thread overlock

It might be difficult to use a four-thread overlock on lightweight and medium-weight fabrics that require additional flexibility. As a result, working with Chiffon and Georgette may be difficult.

On knitted materials, using a four-thread overlock may result in thicker seams, which you may not like.

While a four-thread overlock is often used for most textiles, it is not appropriate for all types of apparel. Even though it is inexpensive and widely available, it is not suitable for lightweight fabrics like chiffon and georgette.

A four-thread overlock would be inadequate for these materials since they require a more flexible stitch and less bulky seams.

What’s the Difference Between Three-Thread and Four-Thread Overlock?

While both may be used on various textiles, certain characteristics set one apart from the other. The three-thread overlock is appropriate for lightweight and medium-weight textiles, whereas the four-thread overlock is appropriate for medium-weight and heavy-weight fabrics.

When making less bulky seams for knitted or woven materials, the three-thread overlock is the ideal option. You may sew heavy-weight materials or textiles that don’t mind thicker seams or hems using the four-thread overlock.