It is important to know the amount of thread consumed in a sewn product so you can:
Estimate the number of cones needed and calculate the cost of the thread needed to manufacture the finished product. Thread consumption can be determined in several ways.
To calculate the amount of thread in a seam, you can:
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Measure the actual amount of thread consumed in a specific length of seam.
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Calculate the thread consumption by using mathematical stitch formulas based on the thickness of the seam and the number of stitches per inch.
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Calculate the thread consumption using thread consumption estimates.
Measuring Actual Thread Consumed
A specified length of the seam, for example 3 inches, is measured on the seam and then the thread is removed by carefully unraveling the stitch. You can then calculate the amount of thread consumed in one inch and multiply this factor times the total length of the seam measured in inches.
Example:
Length of seam= 42 inches or 1.17 yards.
Stitch and seam construction: 401 SSa-1.
Specified length of thread removed from a seam equals= 3 inches.
Needle thread removed = 9 inches
Looper thread removed = 8 inches
Calculation:
Needle thread factor = 9/ 3 = 3 inches of needle thread per inch of seam.
Looper thread factor = 8/ 3 = 2.67 inches of looper thread per inch of seam.
Total needle thread consumed = factor 3 X 1.17yds = 3.51 yds
Total looper thread consumed = factor 2.67 X 1.17yds = 3.12 yds
Total Thread = 3.51 + 3.12 = 6.63 yards per seam.
Generally, a 15 to 20% waste factor is added due to chaining-off, thread breaks, repairs, etc.
If a waste factor of 15% is selected then,
Total Thread= 6.63 yards/seam X 1.15 = 7.62 yards/seam
Obviously, you must do this for each seam to determine the total amount of thread consumed in the finished product.
Technical Thread Consumption Formulas
Thread Consumption depend on number of thread consumption formulas for various stitch types based on the stitch length and thickness of the seam. These mathematically derived consumption factors can be multiplied times the length of the seam to estimate the combined amount of top and bottom thread.
Example:
Stitch and seam: 401 SSa-1
Stitches per inch: 8
Thickness of the seam: .075 inches (measured with a micrometer)
Length of the seam: 42 inches or 1.17 Yds.
Union Special 401 Chain stitch Chart |
|
Seam Thickness |
8 SPI |
0.0550.0600.0650.0700.075 |
4.884.965.045.125.20 |
Consumption based on the mathematical equation:
C = 4 + 2TS
C = 4 + 2(.075 X 8) = 5.20
T = Thickness of The Seam
S = Stitches Per Inch
Actual Required Thread= 1.17 yds X 5.20 = 6.08 yds / seam.
Total Thread required= 6.08 X 1.15 = 7.00 yds/ seam (15% waste factor)
Practical Thread Consumption System:
Seam Length (Inch) x M/C wise Thread per Inch
Thread Consumption = ----------------------------------------------------------------------- + Wastage%
39.37 (Convert in Meter)
Machine Wise Sewing Thread Consumption Per Inch
Sewing thread consumption depending on type of Machine:
Machine Name |
Classification |
Thread/inch |
Wastage% |
Plain Machine |
1 Needle |
3" |
5 |
2 Needle |
6" |
5 |
|
Over Lock |
3 Thread |
13" |
7 |
4 Thread |
18" |
7 |
|
5 Thread |
22" |
7 |
|
Flat lock |
2 Thread |
9” |
7 |
3 Thread |
12" |
7 |
|
4 Thread |
17” |
7 |
|
5 Thread |
27" |
7 |
|
Feed of the ARM |
For one needle |
9" |
7 |
Kanchai Stitching |
For one needle |
7" |
7 |
Back Tape Stitching |
For one needle |
7" |
7 |
|
|
|
|
Bar tack stitching |
7" Per Operation |
5 |
|
Button hole stitching |
7" Per Hole |
5 |
|
Button Attaching (2 hole) |
3" Per button |
5 |
|
Picoting Stitch |
16” |
7 |
Example:
Length Side Seam= 42”
Machine = Over Lock- 4 Thread
42 x 18
Thread Consumption = ------------------ (1+ 7%)
39.37
= 20.5 Meter
After this you must include another 15% sewing thread before place the work order.
Estimating Thread Cost
The thread cost can be estimated by multiplying the thread consumed times the cost of thread in the same units.
For example:
Men’s Dress Shirt thread consumption with 25% waste factor = 131 yds.
Average Cost of T-24 Poly Wrapped Core Thread = $4.50 / 6000 yard cone.
Cost per yard = $4.50 ¸ 6000 = $.00075/yard
Calculation: 131 yds /shirt X $.00075/yard = $.09825/shirt
Sewing Thread Consumption per Body
Sewing thread consumption is very important for the garments costing. For quick costing we use our previous idea to calculate the sewing thread cost. Please find below an approximate sewing thread consumption list for some common item. This list is based on minimum wastage. So, at first please check your percent of wastage & and try to control it.
Item |
Consumption Of Sewing Thread / Body |
Basic T-shirt |
125 mtr |
Basic Polo shirt |
180 mtr |
Basic L/slv Woven Shirt |
150 mtr |
Basic S/slv Woven Shirt |
125 mtr |
Classic L/slv Woven Shirt |
175 mtr |
Classic S/slv Woven Shirt |
150 mtr |
Basic shorts |
350 mtr |
Classic Shorts |
450 mtr |
Basic L/pants |
350 mtr |
Classic L/pants |
450 mtr |
Basic Nylon Jogging Suit |
500 mtr |
Basic Short all |
350 mtr |
Classic Short all |
400 mtr |
Basic Overall |
400 mtr |
Classic Overall |
500 mtr |
Padded Coverall |
450 mtr |
Basic Romper |
350 mtr |
Classic Romper |
450 mtr |
Night Dress |
200 mtr |
Pajama Set |
450 mtr |
Skirt |
300 mtr |
Panty |
50 mtr |
Brief |
50 mtr |
Brassier |
100 mtr |
Corp set |
150 mtr |
Tank Top |
50 mtr |
Denim 5 Pocket Pants |
400 mtr |
Basic Nylon Padded Jacket |
350 mtr |
Classic Nylon Padded Jacket |
500 mtr |
Denim Jacket |
450 mtr |
Twill Jacket |
450 mtr |
Basic Nylon Wind Breaker |
300 mtr |
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