|Knob body: Black technopolymer plastic (Polyamide PA), smooth, glossy
Threaded stud: Stainless steel, European Standard No. 1.4567 (American Standard Series 304 Cu), molded-in
||GN 421.11 hollow knurled knobs have a ball end whose diameter is smaller than the core diameter of the thread.
In clamping applications, the partially
protruding steel hub of the knurled knob prevents chipping of the plastic.