The document discusses 8 different types of seams classified by the British Standards Institution. It begins by introducing seams and their purpose in apparel manufacturing. It then provides definitions and diagrams for each of the 8 seam classes: Class 1 - Plain Seam, Class 2 - Lapped Seam, Class 3 - Bound Seam, Class 4 - Flat Seam, Class 5 - Ornamental Seam, Class 6 - Edge Neating Seam, Class 7 - Applied Seam, Class 8 - Waistband Seam. Popular sewing machines used in garment industry such as buttonhole and overlock machines are also described.

1. 8 CLASSES SEAM
Author- Younus Miraj
Shanto-Mariam University of Creative & Technology
UTTARA-DHAKA

2. INTRODUCTION
In apparel manufacturing seams are former when two or more pieces of fabric are joined by
stitches. Seams have three dimensions: length, width & depth.Seam is the join between two
& more plies of material. Seams are usually formed by welding, adhesives, stitching or other
joining means are sometimes used.According to British Standard Seam is the application of a
series of stitches or stitch types to one or several thickness of material for functional or
decorative purposes. There are a number of different types of seams that have been developed
over the years to do different jobs. While many seam have largely been superseded by the
development of machine stitches that finish as you sew them, and by the development. it is
useful to know some of the basic seams types and finishes. A lack of expensive machinery
need not prevent you sewing the garments you want. Also, some of the older methods have
never been bettered. Here I am concentrating on machine sewn seams using a standard
straight stitch machine.
WHAT IS SEAM?
Seam is the combination of stitch which makes line to join two ply of fabric. Seam is Used as
functional purpose. Sometimes,it used as decorative purpose.When you have chosen your
fabric and pattern, you need to think about the most suitable way to sew the garment together.
This will depend partly on the type of fabric, partly on the use the garment will get, and partly
on the finish you want.
PROPERTIES OF GOOD SEAM
There are given the below properties of good seam:
Smooth fabric joints
No Missed or Uneven stitches
No damage to the material being sewn
Achievement of strength, elasticity, Durability, security and comfort
Comfortable while garment is in use
CLASSIFICATION OF SEAM
Seam construction– Categorized by the British Standards Institution (BS 3870 PART II:
1991, also ISO 4916:1991). The Stitched seams are divided into eight classes:
Class 1 -Plain seam & French seam (SI Seam)
Class 2 -Welt seam or Lapped seam
Class 3 -Bound seam
Class 4 -Channel seam or flat seam
Class 5 -Ornamental seam
Class 6 -Edge neatening
Class 7 –No title
Class 8 -No title

3. CLASS 1 –SUPER IMPOSED SEAM
SEEM DEFINITION:
The seam of class-1 is called superimposed seam. This is the most common & mostly used
seam for joining fabrics. In this seam, two plies of fabric are placed on one another perfectly
& then the fabrics are sewn. The sewn edges of the fabrics remain in the same side.
SEAM DIAGRAM:
USED:
 Attaching fabrics.
 Collar, Cuff sewing, Cuff topstitching.
 Collar band attach sewing and top stitching
 Side seam and sleeve attach with safety-sticker.

4. CLASS 2- LAPPED SEAM
SEEM DEFINITION:
Formed by lapping two pieces of component, they are produced with minimum of two
pieces of component. One component is limited on one end and the other is limited on
the other end. The limited edges of these two components are put in opposite
directions.
In this category of seams in which two or more plies of fabric are overlapped with the
raw edges exposed (for fabrics resistant to raveling) or the seam allowance is folded
under and stitched with one or more rows of stitching.
SEAM DIAGRAM:
USED:main seaming of denim jackets, jeans, and overalls. Fabrics that will not ravel,
unlined garments, side seams of shirts, joining lace to another fabric, attaching patch pockets,
decorative finish

5. CLASS 3- BOUND SEAM
SEAM DEFINITION:
Constructed by binding the component edge with another narrow component. The seam
produced with minimum of two pieces of component. One component is limited on one end
and the other is limited on both ends.
In this category of seams in which the raw edges of the seam allowance of one ore more plies
of fabric, are covered with a bias binding and stitched with one ore more rows of stitching.
SEAM DIAGRAM:
Used: finishing necklines, sleeves hems, inside waistbands of trousers and pants, finishing
seams on unlined jackets and coats, adding interest as a design or decorative detail, finishing
raw edges, continuing the motif design of lace.

6. CLASS 4: FLAT SEAM
SEAM DEFINITION:
Two pieces of fabric are laid flat with their edges closing each other without
overlapping. Seams are produced with minimum of two pieces of component.Both
components are limited on one end but they are put opposition to each other on the
same level.
In this category of seams in which the raw edges of the fabric plies are abutted or just
slightly overlapped and joined together with stitching that covers the joint. Flat seams
do not contain seam allowances, reducing fabric usage but increasing thread quantity.
SEAM DIAGRAM:
Used:close fitting garments where the seam allowance may put pressure on the body, high-
stretch fabrics athletic apparel, shape wear, undergarments, lingerie, thermal underwear,
swimwear, sweatshirts with side panels or with raglan sleeves, eliminating bulk at seams,
seaming pelts

7. CLASS 5: ORNAMENTAL SEAM
SEAM DEFINITION:
A seam class is used for decorative sewing on garments. Seams are produced with
minimum of one piece of component, with unlimited edges on both ends.
In this category of seams that add ornamentation to one or more plies of fabric by
creating straight or curved lines or a designated design.
SEAM DIAGRAM:
Used: Adding a design detail,cording, piping, tucking, welting, box or inverted pleating,
decorative stitching.

8. CLASS 6: EDGE NEATING SEAM
SEAM DEFINITION:
Stitching work made on the fabric edges for neatening. Seams are produced with one
piece of component. This seam has one limited edge on one end.
In this category of seam constructed with one or two plies of fabric used to finish the
edge of a garment or item. There are three finishing types within the classification.
First, secures a folded edge to the shell fabric by stitching, either on the face or
back.Second, stitching is used at the edge or to cover the raw edges, and may or may
not be folded.Third, applies a binding on a single ply of a seam allowance to finish
raw edges.
SEAM DIAGRAM:
Used:To protect the fabric edge such that the warp yarns of the fabric cannot easily open.

9. CLASS 7: NO TITLE SEAM
SEAM DEFINITION:
A narrow piece is sewn to the edge of a garment part. Seams are produced with minimum of
two pieces of component. One component is limited on one end, and the other narrow one is
limited on both ends.
SEAM DIAGRAM:
Used:These are sometimes called applied seams because they are mainly used to a
decorative material to an edge of seam such as lace-elastic.

10. CLASS 8: NO TITLE SEAM
SEAM DEFINITION:
Only one piece of component involved in construction the seam, stitches are applied on its
edges.Seams are produced with minimum of one piece of component with a limited edge on
two ends.
SEAM DIAGRAM:
Used:
 Mainly one piece of fabric used.-
 This class is commonly used for waist belts and belt loops.
 The edge of fabric is sewn by folding in various ways.

11. SEWING MACHINE
After receive the garments components from cutting section, all the garments
parts are joined and sewn as sequentially. Obviously all the components are
sewn respects on buyer requirement.Sewing section is the most important
department of a garment manufacturing industry. Sewing machines of different
types are arranged as a vertical line to assemble the garments. Sequence of types
of sewing machine arrangement depends on sequence of assembling operations.
POPULAR SEWING MACHINE IN GARMENTS INDUSTRY
There are discussed the below popular sewing machine in garments industry:
1. One needle lock stitch machine
2. Over edgemachine of stitch class 500
3. Two thread double chain stitch machine for stitch class 400
4. Cover stitch on interlock machine stitch class 600
5. Feed of the arm hole machine
6. Button hole machine
7. Button sewing machine
8. Bar take machine

12. ONE NEEDLE LOCK STITCH MACHINE
Machine Process
The oil supplied and returned system is improved already, we can adjust the
front/back slant angle of feed dog freely, to reduce the crinkle possibility and
the stitch error between up/down feeding material. New style lifting presser foot
is very easy and reliable, can debase the malfunction rate greatly, and the
operation is very convenient and agile, We can adjust the needle distance for
forward and reverse stitch, based on new design, to guarantee to sew forward
and reverse stitch smoothly and placidly.
Used: it is used pant, shirt, garments and all parts of apparel.

13. OVEREDGE MACHINE OF STITCH CLASS 500
Machine Process
The stitch types in this class are formed with one or more groups of threads, and
have as a general characteristic that loops from at least one group of threads
pass around the edge of the material. The loops form a narrow band of stitching
along the edge of the fabric with threads intersecting at the edge and preventing.
Fabric is fraying.All have high elasticity, they do not unravel easily, and
trimming knife on the machine ensures a neat edge prior to sewing. These
stitches are often called over edge, overcast, over lock, serge, or marrow.
Used:These stitches are best used for edge finishes and hem.

14. TWO THREAD DOUBLE CHAIN STITCH MACHINE OF STITCH CLASS 400
Machine Process
(Multithread chain stitch) required 1 or more needle threads that form loops as
they pass through the fabric and inter. Loopwithfabricandinterloopwiththe
looped threadon the underside. Compare to the 100 class, The 400 class is more
durable and used extensively on apparel. The 400 class use upper needle thread
and a looped to carry the lower .The chain stitch elongates when extended.
Used: Good for setting elastic in waist bands or decorative stitching on belts
and Parallel rows of stitches for lapped side seams of woven shirts and jeans.

15. COVER STITCH ON INTERLOCK MACHINE OF STITCH CLASS 600
Machine Process
Interlock Machine is a high speed with 3 Needles, and 5 Threads. The machine
includes a New Style Dial Micro type stitch length regulator; Differential feed
Adjustment and Fully Automatic Lubrication.Interlock stitch machine with
cover thread for plain seaming. This versatile machine can be used for special
machine by changing accessories, since cylinder bed is very small, sewing very
small tubular goods, such as sleeve and neck openings. Improve base line cam
structure, and move came outside, so that the base line cannot enwind cam; even
if it enwind, can solve easily, increase cam anchor point in order to load and
unload conveniently, more efficiency.
Used: It is used T- shirt, Trouser and so on.

16. FEED OF THE ARM HOLE MACHINE
Machine Process
This machine demonstrates increased feed efficiency to handle extra heavy
weight 16-ply denim and Engineered with extra feeding strength for seaming
the inside of jeans. The machine is best suited for lap seaming jeans, denim
jackets, work uniforms, etc. constructed of heavy weight materials.
Used: Side seam and under arm.

17. BUTTON HOLE MACHINE
Machine Process
A machine-made buttonhole is usually sewn with two parallel rows of
machine sewing in a narrow zigzag stitch, with the ends finished in a
broader zigzag stitch.
A bound buttonhole, which has its raw edges encased by pieces of fabric
or trim instead of stitches.
A keyhole buttonhole is a special case of a thread-finished buttonhole that
is normally machine-made due to the difficulty of achieving it by hand
working. It is characterized by a round hole at the end of the slit to
accommodate the button's shank without distorting the fabric.
Used: it is used making button holes.

18. BUTTON SEWING MACHINE
Machine Process
1. Attach the button sewing foot, or remove the pressure foot and work with the shank
only.
2. Lower the machine's feed dogs.
3. Select a zigzag stitch.
4. Set the stitch length to 0.
5. Place your fabric and button under the machine. You should have already marked
your fabric with your buttons position.
6. Lower the foot (or shank) down onto the button to hold it in place.
7. Using the hand wheel on the side of the machine, lower the needle into the left hole of
the button. You may need to re-position the button a little to get the needle to clear the
button hole perfectly.
8. Still using the hand wheel, raise the needle so the needle moves to the right position
(the right-most edge of the zigzag stitch).
9. Lower the needle so it hovers just above the button. You're going to 'eyeball' the
position of the needle as you adjust the stitch width to determine when the needle will
clear the right hole of the button perfectly.
Used: Attaching button to front placket and cuff.

19. BAR TAKE MACHINE
Machine Process
At first this machine produces tack stitches in a small length (1-2 cm) and then
sews covering stitches over and at right angles to the first stitches. The variables
are the number of tacking stitches and the number of covering stitches. Typical
uses are closing the ends of buttonholes, reinforcing the ends of pocket
openings and the bottoms of flies and sewing on belt loops. The adjustment
points of this machine are needle, pressure feed, stitch length, stitch density.
Uses of Bar Tack Sewing Machine:
1. Attaching belt loops.
2. Increasing strength in corner of pocket.
3. Closing the two corners of button hole.
4. At the end of zipper.
5. In that place where more strength is needed to support extra load.