"Mike Lyle" wrote in message
oups.com...

michael adams wrote:
"Graham Knott" wrote in message
...
I received no instructions with the new blade and the retaining nut on
the
mower is jammed.
In which dirction does the nut rotate to unscrew it?
Thanks.



On most rotating components the threads are in the opposite
direction to the rotation, so that things can't become
unscrewed in use. This can make them more difficult to unscrew
as they tighten up in use and you make need a hollow pipe over
the spanner to increase the leverage.

You should be able to work out the rest for yourself.

Tip: gently heat the nut (_not_ red-hot!) with a blowlamp, then tap
gently with a hammer to break the scale. It should then come free
easily. I can never remember, but I think they're all standard
right-hand threads -- I imagine it would make production engineering
sense.

....

The threads on left and right handed bicycle pedals and bottom brackets
are opposite threaded so as not to unscrew in use.
Threads on oxygen gas cylinders and fittings are right handed
while threads on acetylene gas cylinders and fittings are left handed
so as to prevent explosions etc.


....


Use a socket or ring spanner, even if you have to buy it specially: you
don't want open-ended spanners slipping under pressure in the
neighbourhood of a blade.

Beware petrol; and you will disconnect the spark-plug first, won't you?
Please.

....

Er, not necessary.




michael adams

....


--
Mike.