What is a single needle lock stitch machine? Detailed guide in 2023

What is a single needle lock stitch machine

Currently, you have access to various sewing machines depending on your needs and designs. Did you ever wonder what is a single needle lock stitch machine? You’re probably not going to because you’re accustomed to industrial, mechanical, serger, etc., sewing machines, but this is unusual. 

This is why I will go over every detail of this type of sewing machine. You should proceed to the end of this article to better understand it. 

This article will frequently use two terms that need to be understood before we discuss single needle lock stitch sewing machines.


A type of stitch made by a sewing machine which creates a firm stitch while binding the thread so that it stays in place. 

In this type of stitch, upper and lower threads are intertwined tightly to create a new stitch called lockstitch. 

According to Merriam-Webster dictionary, the definition of lockstitch is a sewing machine stitch formed by the looping together of two threads, one on each side of the material being sewn.

For a better understanding, see the picture:

What is a single needle lock stitch machine
Source: Wikipedia

Lockstitch sewing machine

A type of industrial sewing machine that produces lockstitch by interconnecting two threads, one coming from a needle and the other coming from a bobbin

Lockstitch Sewing Machines sew straight and strong seams, making them very successful industrial sewing machines. Furthermore, Lockstitch sewing machines are available in mechanical and computerized versions. 

Walter Hunt patented the first lockstitch sewing machine in 1832. 

I hope you have a clear understanding of Lockstitch and Lockstitch sewing machines. 

Let’s move on to the primary point. 

What is a single needle lock stitch machine?

With its single needle and one bobbin, single-needle lockstitch sewing machines are commonly used to create lockstitch on fabrics. 

It differs from a double-needle lockstitch sewing machine in that it consists of one needle and one bobbin, while a double-needle device has two needles and two bobbins. 

Features of a single needle lock stitch sewing machines

  • Due to its single needle, it is called a single-needle machine. 
  • It is an Industrial sewing machine. 
  • The main needle and bobbin are on a single-needle lockstitch sewing machine. 
  • One of the benefits of this sewing machine is that it contains two threads, one from the needle and one from the bobbin, and interconnects them to make a lock stitch. 
  • On fabrics, it makes a single parallel stitch.
  • It has an automatic thread trimmer that cuts threads when sewing is halted. 
  • Single needle lockstitch machine is mainly used in woven garments manufacturing. 
  • Needle thread sews on the upper side of fabrics; bobbin thread sews on the lower side. 
  • Only lockstitch is made on this sewing machine. 
  • Single needle lockstitch sewing machine operates at a speed of 4000-5000 revolutions per second (RPM). 
  • This lock stitch sewing machine can make around 7 to 9 stitches per inch thanks to its SPI of 7-9. 

Sewing fabrics with single needle lock stitch

Every sewist can sew the following fabrics with this sewing machine;

  • Shirts.
  • Jackets.
  • Suits.
  • Overcoats.
  • Bed sheets.
  • Curtains.
  • Kids Clothes.
  • Bags.
  • Leather.
  • Wool.
  • Chemical fibre.
  • Canvas.

Pros and Cons of a single needle lock stitch sewing machine

  • Edge cutting.
  • Automatic bobbin winding.
  • Noise reduction.
  • Low Vibration.
  • No Radiation.
  • Environment-friendly.
  • Single needle.
  • Straight and strong stitches.
  • Extremely fast.
  • 7 to 9 Stitches per inch (SPI).
  • Seam allowances are left unfinished.
  • Undesirable in ravel-prone fabrics.
  • Rewinding the bobbin is frequent.

What is an essential feature of a single needle lock stitch sewing machine?

The most anticipated feature of this sewing machine is the single needle and the ability to make straight stitches. 

Since it has one needle, it is the most common industrial sewing machine used by 70-80% of users worldwide. 

Needles of a single needle lockstitch sewing machine

Single needle lockstitch sewing machine uses straight needles in sizes 70/10, 75/11, 80/12, 90/14 and 100/16.


In this article, I tried to answer your question, what is a single needle lock stitch sewing machine? This article should provide you with a lot of information on this topic after reading it. 

I recommend you comment on your issue below in the comment section if there is any confusion. 

You can easily understand this topic if you spend some time reading this article. 

Q1: What types of stitches are made by a single needle lock stitch sewing machine?

Ans: As the name suggests, this industrial sewing machine makes a single straight lockstitch sewing machine on fabrics. 

Q2: How many needles does a single needle lock stitch machine have?

Ans: One needle and one bobbin make straight solid stitches by intertwining their threads. 

Q3: Are single needle lock stitch sewing machines worth buying?

Due to Edge cutting, Automatic bobbin winding., Less Noise, Low Vibration, No Radiation, Environment-friendly, Single needle, Straight and strong stitches, Extremely fast, and 7 to 9 Stitches per inch (SPI), it is essential that you buy.