Assembling glassware
Clamping a reaction flask
Clamping a reaction flask
The first part of clamping usually involves attaching the bosshead to the frame in a specific orientation. You should be able to see the screw tightening against the framing, unobscured by the metal groove.
Likewise, the clamp sits on top of the metal groove, so it is supported from underneath should this loosen and fall.
Glassware is clamped firmly around the neck or quickfit glass joint. The lip on the top of the neck should always exceed the clamp jaws, sitting slightly above this level.