We need to figure out sewing thread consumption of various item like T-shirt, shorts, pants and tank tops. As a textile engineer, we need to calculate sewing thread consumption perfectly for costing purpose / bulk production. Sewing thread consumption means how much thread we need to stitch for an garments. To figure out garments thread consumption, we have to pay concentration on sewing machine, number of needles, fabric thickness. We need to calculate how much thread is used to stitch 1 inch by machine. And also we have to consider minimum 10-15% wastage to find out thread consumption of a product. Below information shows you how much thread you need to stitch 1 inch of fabric. By the way, it differs fabric to fabric as on their GSM & fabric construction. If you want to check your self, then you can stitch 10 inches of fabric, now cut 1 inch stitch, measure the length of each thread, now figure out the threads & finally add wastage minimum 10%. It's long process, so better we can memorize information and imagine wastage depending on GSM. For high GSM fabric, we need to increase wastage percentage. If we are working on T-shirt then we have to separate the different stitching of that shirt.
Let's see below information for how much tread you need to stitch one inch fabric by different sewing machine:
 |
| Sewing thread consumption |
| Machine | Needs thread per inch stitch |
|---|---|
| Plain Machine- Single Needles | = 2.75 inches |
| 2 Needles P/M (Plain Machine) | = 5.5 inches |
| 3 Threads O/L (Over lock) Machine | = 15 inches |
| 4 Threads O/L (Over lock) Machine | = 19 inches |
| 5 Threads O/L (Over lock) Machine | = 23 inches |
| Safety stitch | = 20 inches |
| Flat lock Stitch | = 32 inches |
| Chain stitches - 1 Needle Kansai Machine - 2 Needle | = 11 inches = 12 inches |
| Button Hole | = 24 inches |
| Bar take Machine | = 26 inches |
| Button Stitch of 2 Eyes (holes) | = 3 inches |
| Button Stitch of 4 Eyes (holes) | = 6 inches |
Now, let's find out sewing thread consumption with example:
Q.1: Suppose, we want to make consumption on T-Shirt. T-shirt have 90 inches 3 thread over lock stitches, 48 inches flat lock stitches, 18 inches 1 needle chain stitches, 16 inches single needle Plain Machine Stitches, normal GSM is 150. Let's find out the consumption of sewing thread in meters ?
Solution: {(90 *3 thread O/L) + ( 48 * F/L) + (18 * 1 needle Chain stitches) + (16 * 1 needle P/M) + 10% wastage }
= {(90 * 15) + (48 * 32) + (18 * 11) + (16 * 2.75) + 10%}
= { 1350 + 1536 + 198 + 44 + 15%}
= 3597 inches
= 3597 / 39.37 ( 1 meter = 39.37 inches)
= 91.37 meters
Q.2: Suppose, we need to buy thread cones with 4000 meters, Garments qty 2500 pcs, Per body consumption 91.37 meters. Now let's see how many cones need to stitch 2500 pcs of garments ?
Solution: Per body consumption * Garments qty / per cone in meters
= 91.37 * 2500 / 4000
= 57 cone