Torque reduction with lubricated threads

[Donal]

While looking for something else I came across this article. The graph tells it all;

120 ft/lbs with dry (un-lubricated) threads versus 60 ft/lbs with with lightly oiled threads, and 30 ft/lbs with threads lubricated with moly grease to achieve the same residual bolt load.

I know there has been some discussion about the amount you should reduce recommended torque to compensate for lubricating but............

How many people have managed to replace a sump plug and maintain dry un-lubricated threads?

 

[mcatrophy]

Good to see some documented indications.

However,

...How many people have managed to replace a sump plug and maintain dry un-lubricated threads?

in the case of the FJR, never, ever, even approach the torque recommendation for the sump plug.

 

[Donal]

Good to see some documented indications.

However,

...How many people have managed to replace a sump plug and maintain dry un-lubricated threads?

in the case of the FJR, never, ever, even approach the torque recommendation for the sump plug.

Funny, that's what I thought I was saying! Recommended torque for a sump plug is something like 40 ft/lbs FOR DRY UN-LUBRICATED THREADS. It is virtually impossible to maintain dry un-lubricated threads. So................. using the graph, 20 ft/lbs would seem like a good number.

 

[mcatrophy]

I meant, even allowing for it being wet. Too many tales of stripped threads.

sump plug stripped site:fjrforum.com

 

[dcarver]

Cheap Japanese aluminum.

 

[mcatrophy]

Cheap Japanese aluminum.

I learned many moons ago on cheap British aluminium, my old Tiger Cub.

More often than not it looked like this:

(Click on image for larger view)



Stripped one thread on that. Caused so much of a pain to a very, very poor uni-studant that I've never (touches wood) stripped one since. And never owned a torque wrench.