Shear Nut M12, Fits Combilock Trailer Lock A

Shear nut M12 for Combilock trailer lock

Shear nut with M12 thread, also listed as a break nut. It fits the Combilock trailer lock A.

What a shear nut does

A shear nut is tightened until the outer part twists off, leaving behind a head that an ordinary spanner cannot grip. That is the point of it on a lock installation: the fixing cannot simply be undone with common tools. It also makes the nut a one-time part — once it has sheared, it is replaced rather than refitted, so keep a spare with the lock if the installation may need to be taken apart.