Threads
Threads are helical notches that occur on the inside or outside of components and are used to connect them.
In adhesive technology, threads are, besides the usual screws and nuts for fastening, most commonly found on nozzles.
Depending on the associated device, nozzles have internal threads or external threads.
HB 196 with internal thread
HB 250 with external thread
Common thread types in adhesive technology
The most commonly used thread types are:
- UNF 9/16“-18
- UNF 7/16″
- UNF 1/2″
- M10 x 0.75
The American identifier UNF stands for Unified National Fine Thread. Other thread shapes would be, for example UNEF (extra fine) or UNC (coarse thread), but the latter are rarely found in application devices. UNF threads are characterised by the diameter and number of threads per inch (threads per inch, TPI). For example, UNF 9/16“-18 means that it is a UNF thread with a diameter of 9/16 inch and 18 threads per inch.
The more familiar M refers to ISO fine threads (DIN 13ff). The number attached describes the outside diameter in millimetres. As with the UNF threads, the flank angle is also 60°. The number behind it (in the example 0.75) stands for a thread pitch of 0.75 mm.
BÜHNEN nozzles also have the designations
- ET = external thread
- IT = internal thread
to describe the thread on the nozzle.
