Septa and Cap for Screw Thread Sample Vials – Hawach Screw cap vials and screw caps are universal. In the process of tightening the bottle cap, a mechanical force is applied to squeeze the vial septa between the Vials & Syringes – MZ-Analysentechnik GmbH Screw Top Glass, Caps, and Septa for large volume vials (7-60 mL) .