On 25/12/2020 11:04, Dave Plowman (News) wrote:
In article ,
newshound wrote:
Why would you want lubricant on the threads? I've never managed to strip
them.

Because, by reducing friction at that point you get significantly more
axial force, which is what does the sealing, for a given torque. Also,
excess torque can disturb the next joint down the line, as discussed in
another thread. Same reason you were always taught to lubricate all the
studs and nuts when rebuilding a bottom end, so as to get the bearing
caps clamped down as well as possible.

I've never had a problem tightening a compression fitting with dry
threads. With adequate sized spanners.

Indeed, try tightening the nuts on a 22mm butterfly valve in the gap
between the top of a kitchen cabinet and the ceiling, when the only
thing you can get in there is a pair of these:

http://wiki.diyfaq.org.uk/index.php/...eelSpanner.jpg

(admittedly 17 years ago - but that was the last time I needed to use
PTFE on the threads to be able to get the nuts done up tight enough)



--
Cheers,

John.

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