Bernina Sergers

Mastering

Your

BERNINA®

BERNINA® Sergers

MASTERING YOUR BERNINA® SERGERS 2/15/03 8

Thread

Poor quality or the wrong type of thread can cause poor stitches on any

machine. Thread passes through the eye of the needle approximately

37 times in a “seesaw” action before it forms a single stitch. Poor

quality thread results in crooked and looped stitches, puckered seams,

frayed thread, and/or needle breakage. To achieve quality stitches, an

overlock machine needs three things: correct thread, correct size

needle, and properly adjusted settings.

Several factors such as the fiber, twist, ply, finish, and size of thread

must be considered for use with today’s fabrics for fine stitches.

Staple – refers to the length of fibers used to twist together to form a

single ply. Domestic thread fiber lengths are usually 1½” to 2½” long

while European threads use 5½” to 6½” lengths.

Ply – number of strands twisted together to make a single thread.

Roll – the tendency of thread to roll to the right or left during

stitching, causing the stitch to appear slightly crooked. Poor quality

threads are more likely to roll.

Twist – the crimping of fibers which causes them to interlock firmly into

a single ply. Thread should not untwist during stitching. This will cause

skipped stitches, thread breakage, crooked stitches, and weak spots in

seams.

Right twist – most American

threads are twisted to the right,

causing some rolling. This gives

average stitch quality.

Left twist – Most commercial and

imported threads are twisted to

the left, giving better than average

stitch quality. Left twist resists

rolling and makes a larger loop for

the hook point to enter, reducing

skipped stitches.

Notes