23-05-2020, 05:39 PM
I agree with Alan's friend.
That's not to say self-locking nuts aren't secure, only that they work in the same way that plain nuts do. It's not the insert that keeps them done up.
The 'locking' feature, if it works at all, will only come into play when the joint has technically already failed, at best it may provide some damage limitation.
At worst, nuts which use heavy friction between the nut and bolt cannot be accurately torqued down due to variations in this friction, which positively undermines the integrity of the joint. Nylocs are probably the least susceptible to this and thus my self-locking nut of choice.
I can't speak for the entire motor industry but my own employer is particularly fussy about bolted joints and doesn't use self locking nuts in any critical joint - plain nut and carefully established tightening torque every time.
That's not to say self-locking nuts aren't secure, only that they work in the same way that plain nuts do. It's not the insert that keeps them done up.
The 'locking' feature, if it works at all, will only come into play when the joint has technically already failed, at best it may provide some damage limitation.
At worst, nuts which use heavy friction between the nut and bolt cannot be accurately torqued down due to variations in this friction, which positively undermines the integrity of the joint. Nylocs are probably the least susceptible to this and thus my self-locking nut of choice.
I can't speak for the entire motor industry but my own employer is particularly fussy about bolted joints and doesn't use self locking nuts in any critical joint - plain nut and carefully established tightening torque every time.