Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Screw configuration. The screw diameter is 20 mm. Single letters correspond to the manufacturer’s screw part codes as presented in the top left corner, where SE—conveying element, KBW—kneading block, R—forward element, L—reverse element, and numbers encode angle (KBW only), step and element lengths in mm.
