head nuts

[Niallcat]

Just curious as to why virtually every nut and bolt has a locking device except head nuts ? I’m sure there must be a reason? TIA Niall

[flying farmer]

Can't say I have ever thought of this before, but I should imagine that a locking system would distort the torque setting figures.

Since they never vibrate loose a locking system isn't needed, never seen any form of locking system on any engine I have ever worked on.

Neil

[Motorsport Micky]

As Neil says above, nyloks or secure lock threads all rely upon interference of the turning motion...that's what they are designed to stop, stopping it one way stops it every way and would screw up the measurement of torque.
No...and don't try adding split washers, if hard enough they invariably crack under the applied torque because of being split and the flexing imposed which then releases the clamped load, and if not hard enough they gouge up messing up the applied torque.

Micky