These needles are meant for Coverlock and overlock machines for working with different fabrics. They are covered with a chrome coating which makes the needle smoother. The letters CF stand for Chrome Finished

Sewing machine needles by Schmetz are world renowned for excellent quality.
These are slightly longer then universal needles and are used in Coverlocking and Overlocking machines. Suitable for a wide variety of fabrics, see the attachment tab for more info


See the owners manual of your machine for the correct needles...

Special features:
For household coverlock or overlock machines whose operating instructions specify 
the use of the needle system ELx705, ELX705 CF, ELX705 CR or SY 2022
Flat shank
Overlock needles with a second thread groove to create chain 
stitches such as overlock or coverlock

Have trouble choosing?
Find an overview for the combination of fabric, thread and needles here: (dutch) 
Garen en naalden gebruikstabel
TIP: a needle has a working life of 8 hours.

That does not mean you have to change your needle after one day. It more like this: If you press the pedal of your sewing machine down and hold it down for 8 hours straight, then you need to change the needle.
The easiest to remember is to have a new needle every time you start a new project