[TR] nuts, bolts and lock washers

[Randall]

 DLylis at aol.com write :

>  Does a grade 2 lockwasher present less "lock" than a grade 5, which
presents less than a grade 8?

Again let me emphasize that I'm no expert; but I believe the answer is no.
Surely there is an ME out there somewhere ?

>  Also, which is better to use in appropriate applications, a lockwasher or
a nyloc?

Nylocs are not suitable for locations with high heat (like manifold nuts),
while lockwashers are not suitable for bolts that get a lot of torque
relative to their diameter (and grade).  Other than that, I don't know
(except that lockwashers are a lot cheaper to replace and they both
frequently need to be replaced).

> Is it wise to use a nyloc in place of a castellated nut with split pin?

Seems to be OK, as long as there is no chance of it getting hot (so not on
wheel bearings).  But again, a cotter is a lot cheaper to replace every
time; and IMO any Nyloc in a safety-critical location should be replaced
every time.  Even one remove/install cycle reduces the torque to turn them;
especially if the exposed threads were a little bit rusty or dirty.

> The nylocs I have available are only grade 2,

MMC offers them in grade 5 and 8 (as well as 2).
http://www.mcmaster.com/nav/enter.asp?pagenum=3112

But since I tend to go with the original fastener (unless I have a good
reason to change), and AFAIK the originals were the equivalent of grade 2, I
mostly use grade 2.  The exception is the driveshaft flange bolts, where
I've had trouble with even new Nylocs backing off.  Perhaps my driveshaft is
somewhat out of balance or something.  Anyway, I now use what MMC calls
"oval lock conical top" nuts there, which only come in medium hardness
(roughly grade 5) steel.
http://www.mcmaster.com/nav/enter.asp?pagenum=3115

Randall