There are various ways of securing threaded fasteners against vibration loosening in machines, and Henkel Loctite is highlighting this one
LOCTITE 243 is a medium strength threadlocker that secures all types of threaded fasteners. In use, the material also offers a high degree of protection for nuts, bolts and studs. Loctite says that whilst there are exceptions in some cases, its LOCTITE 243 will nevertheless prove suitable for the vast majority of standard threadlocking applications, which we think its fair to say will include many machine building applications.
Threadlockers offer an added advantage by strengthening threaded assemblies against vibration by adding somewhere in the region of 25% to the torque needed to loosen a normally tightened bolt assembly according to Henkel. A further advantage cited in favour of threadlocking is that unlike mechanical locking devices, one tube of threadlocker fits all sizes of threaded fasteners and rods, allowing machine builders to reduce inventory and thus costs.
One aspect not commonly recognised is that in the case of LOCTITE 243, it is tolerant to minor oil contamination and can cure on ‘as-received’ fasteners without cleaning says the company.