Glass screw threads manufactured from Borosilicate glass are used in a variety of laboratory glass applications. Combined with PTFE sealing rings the screw threads can securely hold items in place.
Alternatively, removable parts like hose connections can be applied or the thread can simply be closed off using a blanking cap and seal.
Screw threads are often combined with ground glass cones to form a scare thread adapter. These are available in a vast array of sizes.