kashew Nov 6, 2015:

Activator patch See http://www.loctite.fr/loctite-5845.htm?nodeid=8802624012289

alex.saviano (asker) Nov 6, 2015:

other instances... Hex flange screw (B) is installed with a thread lock patch that can be used for up to three installations.

Hex Flange Screw, M12 x 60—10.9 (with thread lock patch)

....

Tony M Nov 6, 2015:

thead-lock patch I'm pretty sure that this 'patch' is not actually an adhesive (in the sense of the Loctite mentioned) but probably something more like the nylon inserts used in Nyloc (r) nuts etc. This would explain both the use of the term 'patch' and also the fact that it could be worn.