Needle Thickness

Machine needle thickness increases as size increases.
Example: Size 18 is thick.

But with hand sewing needles, thickness decreases as size increases.
Example: Size 12 are sliver-thin.

American sizes are on top row; European sizes on bottom row.

Machine Needles

Size 8 9 10 11 12 14 16 18
mm 60 65 70 75 80 90 100 110

Deciphering Twin Needles

2.0/80: 2.0 is mm between needles, 80 is needle size.