Button Hole Machine: Parts, Specification and Working Principle

Last Updated on 18/04/2021

Name of the Experiment:
Study of Industrial Button Hole Machine.

There are many types of sewing machine. Some are used for special purposes such as Button Attaching machine, Bartack sewing machine etc. This type of machines works in a cycle and so these are called simple automatic machine. Here we study on a type of machine that is Button hole machine. For example if you are sewing a shirt and need to make a few button holes then a buttonhole attachment (or built in button hole mode of a general purpose machine) would work fine, but for production work in a clothing factory a special purpose industrial buttonhole machine would be much faster and more reliable.

button hole machine
Fig: Buttonhole machine


  1. To know about the parts of button hole machine.
  2. To know about the thread path of buttonhole machine.
  3. To draw the thread path diagram of button holing machine.
  4. To know the working principle of button holing machine.
  5. To know the types of needle, its no, size, SPM, group, TPI of the machine.
  6. To know about the buttonhole sewing machine.

Specification of buttonhole machine:

  • Brand : JUKI
  • Model : LBH/781
  • Group : Lock stitch
  • Needle use : DPX5
  • Needle size : 9, 11, 14, 16, 18, 20 and 21
  • SPM : 3000-3600
  • TPH : 6-7 inch
  • Pressure : 123

Different parts of button hole machine:

  1. Bobbin winding
  2. Bobbin winding spring tensioner
  3. Back stitch lever
  4. Driver wheel
  5. Driven wheel
  6. Spring tensioner post box
  7. Thread guide
  8. Knife lever
  9. Thread take-up lever
  10. Needle
  11. Knife
  12. Wiper
  13. Pressure feed guide
  14. Throat plate
  15. Bobbin
  16. Bobbin case

Main adjustment points of buttonhole machine:

  1. Thread.
  2. Tensioner.
  3. Needle.
  4. Pressure feed.
  5. Stitch density.
  6. Looper.

Working principle of button hole machine:
This machine works in cyclic system i.e. during pressing switch after sewing one complete button hole the machine will stop. In fully automatic button hole machine more than one i.e. pre-selected no. of button holes can be sewn in pre-selected distance. In this system no mark is needed on cloth for button hole. In buttonhole machine there is system to make big or small button hole and also to increase or decrease the stitch density. Usually lock stitch or chain stitch is used here. Button hole can be made before or after sewing. Both system has some advantage and disadvantage. If hole is made before then the cut edge is closed in sewing and the button hole is seen very good and clean. But the disadvantage is that after starting sewing there is no chance to change the button hole place and cut edge disturbs to sew well due to flagging. But disadvantage is thread of cloth is come out along the sewing line of button hole that looks very bad. Usually for dense woven and coarse cloth before sewing, for thin cloth after sewing button hole is made.

Diagram and thread path of Button Hole machine
Fig: Diagram and thread path of Button Hole machine

A = Cone package
B = Guide
C = Guide
D = Spring box tensioner
E = Guide
F = Guide
G = Tensioner
H = Thread cutting ever
I = Take up lever
J = Trimming lever
K = Guide
L = Guide
M = Throat plate
N = Cutting knife

Uses of buttonhole machine:

  1. To make button hole in different apparels.
  2. Sewing of button hole.

Buttonhole sewing machine cannot be used for normal purpose. But for making a complete garment it’s importance cannot be denied. It is used for making button hole in different garments. These machines make button holes at high speed and with greater precision then with a button hole attachment on a sewing machine. Some machines can run at 4000 SPM or greater. Special care and sufficient knowledge is necessary for proper working. Otherwise faulty sewing may be done. I would like to give special thanks to our teacher. I am also grateful to our instructors. I think this will be very helpful in my future life.

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  2. Bartack Sewing Machine: Parts, Working Principle & Uses
  3. Working Aids in Sewing Machine and Garment Production
  4. Sewing Machine Maintenance Schedule
  5. Sewing Machine Engineering and Attachments
  6. Thread Path, Parts & Main Adjustment Points of Overlock Machine

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