Needle/Thread Combination

The needle/thread combination is correct, when the thread fits perfectly into the long groove and goes easily through the needle eye. The thread can be optimally sewn.

The thread can break and skipped stitches can occur when there is too much clearance in the long groove and the needle eye.

The thread can break and get stuck when the thread scrapes against the edge of the long groove not fit well into the needle eye optimally.