Copper Grease on wheel nuts - yes or no?

Fr Dougal

Title says it all.

Just took off back wheel to replace brake pads. Wheel studs were almost siezed on, had to bounce on wheel brace to free them.

Anyway, when putting wheel back on, should I put a bit of copper grease on the threads? Any safety issues?

Thanks in advance.

mike65

No! There is no need, just tighten the nuts correctly, people have a bad habit of overtightening to the point where the nut "creaks".

Mike.

Fr Dougal

Cheers, Tks.

nc19

always good to put a small bit of copper grease on a nut or bolt that will need to be removed again at some stage.
the standard torque setting for normal sized cars is app 110Nm. if your a grown man you should be able to reach app 150Nm, so you dont need to swing out of them when your tightening them

old boy

prob is they are usually fitted with an air gun

crosstownk

If the wheel bolts are torque correctly then there should, in theory, be no problem. But a small dab of any grease that has a high temperature resistance will do. It will assist in easy removal of the wheel nuts at a later stage.

Take, for example, a wheel that is tightened to 110NM (VW spec in late 1990s/early 2000). After a lot of driving and expansion and contraction of wheel hub, brake disc, wheel and wheel stud, sometimes the wheel stud/bolt can get 'sticky'. High temp grease will assist in removal. Even Vaseline will do the trick.

Plug

i always put it on the studs and at the back of the brake pads.

CJhaughey

Any sort of lubricant will allow accurate torqueing of fasteners.
Think about a rusty bolt being torqued the friction can cause incorrect readings on your torque wrench.
Grease or lube the bolt with copper grease and you are far more likely to get an accurate figure.
I always use tiny dab on the wheel nuts and have never found them to be loose, mind you I torque by hand to the required NM setting

youtheman

CJhaughey wrote: »

Any sort of lubricant will allow accurate torqueing of fasteners.

Only if you know the lubrication factor of the lubricant you are using.

If you are torquing a bolt then the objective is to stress the bolt to about 80% or 90% of yield (i.e. in the elastic region of the metal, before you get to the plastic or yield region).

The problem with the anti seize compound is that they have a very low lubrication factor. If, for example, the compound has a lub factor of 0.5 then this means that you have to only use 50% of the normal torque to achieve the end result. Or put another way, if you don't use the correct factor then you use double the torque, and you end up with a metal fastener that has been plastically deformed.

So if you intend to torque a bolt, and you are using copper grease, or some other lubricant, then make sure you do the maths and use the correction factor.

Oilrig

youtheman,

Spot on. Torque figures are usually for clean dry threads unless otherwise stated and are calculated to include friction.

youtheman

Oilrig, with a 'handle' like that I presume you are in the 'oil and gas' business where torquing flanges etc. is a common task.

Oilrig

"Oilrig, with a 'handle' like that I presume you are in the 'oil and gas' business where torquing flanges etc. is a common task."

Nope...