Stitch Type

Sewing stitch terminology

Stitch length:

Measured in terms of the number of Stitches Per Inch. The longer that stitch, the further a sewing machine can sew in the same amount of time (10 SPI faster than 20 SPI).

Lengthening stitches:

Lengthening stitches is an easy way for manufacturers to cut costs.

Stitch tension:

Refers to how loosely or tightly the threads are held by the sewing machine as it sews.

Balanced tension:

Equal tension on needle, bobbin, and/or looper threads.

Lockstitch tension:

Affected by unbalanced tension more than other stitch types. Unbalanced lockstitch tensions causes the

Most affected by tension

fabric to pucker. Balanced tension is crucial for durable lockstitches.

Short stitch advantages:

Contributes to increased stitch strength and durability. Stitches too long or too short may lead to puckering. Short stitches make smaller ruptures in rows of stitches when they break than long stitches.

Less

apt to cause seam grin/tighter seam. Allows the seam to be more extensible.

Needle cutting:

Results when the needle cuts or severs the threads of the fabric rather than slipping between them. CAUSED BY: Too large a needle for fabric type, blunt or damaged needle or wrong type of needle tip.

Needle heating:

Occurs when sewing friction heats the needle. Fuses or melts the finishes or fibers of the thread of fabric. Fast sewing speeds are the main cause of needle heating.

Needle chewing:

Results in jagged, enlarged needle holes in the fabric.

Back tacking:

Secures the stitches, and prevents unraveling. A sign of high quality. Done automatically by industrial sewing machines. 500 and 600 class stitch machines are not capable of back tacking.

Latch tacking:

Draws the excess thread chain at the beginning of each row of stitches into the stitches to secure them. Used for 500 and 600 class stitches.