Nyloc nut re-use 2

[rattler]

Does anyone know please, if there a limit on the number of times you can re-use a nyloc nut?

Thanks

 

[haggis]

rattler,

For the cost of replacing, use once.

Haggis

 

[Screwman]

The number of reuses will depend on the requirement that you have for prevaling trorque on the nut once it is broken loose from the application.

 

[CoryPad]

Typical automotive specifications require a minimum off torque after 5 on-off cycles, so 5 is a place to start.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[evelrod]

Actually in at least one paper from Nyloc that I read while I was over there said that most nuts were a "one time" use item.
Another discussion came up at the time---counterfit nyloc fasteners, indeed, counterfit 'grade 8' fasteners. I got a batch of 5/16th NF nuts that stripped when torqued to over 144 in/lbs. Torque for that application was supposed to be 300 in/lbs.

Rod

 

[rattler]

Thanks everyone. I've just received a fax from my fastener supplier containing an extract from an old Nyloc publication that claims "Nyloc nuts can be re-used many times without impairing their self-locking action". It details various successful tests where rundown torques were measured after a number of removals. I'm happy to follow this advice in my current application, as the consequence of the nuts undoing is not safety critical.

Thanks

Rattler