Castle nuts and correct torque

In the aviation world, we use a multitude of hardware that is either safety wired or cotter pinned. the common practice is to use a thin washer under the nut if it won't make torque up with an acceptable alignment. The next option is to go on to the next castellation but sometimes it stretches the threads & fastener too much. FoMoCo used pal nuts on the con rod caps in the early 8BA era but finally realized that if properly torqued, a pal nut was not necessary. Aerospace still has a practice of double safety on all control system hardware but there are several ways to do it. Some, like Robinson Helicopters, still use pal nuts. Others use castellated elastic stop nuts and cotter pins.
 
DWester said:
Would you do the same for the rods Ron? When I took this motor apart, it had keeper/retainer nuts behind the rod nuts.
Click to expand...


Just use Chevy 350 rod nuts they will work just fine.Install them and torque and they will never come loose. There are 100,000,000,000 + of them running down the freeway all day long.:)

R
 
Just threading some wire through the holes is not really "safety wiring" it! If you look at some wiring jobs, you can visualize the bolt/nut backing off a quarter turn or more before the wire does any good. Oops, too late! There is an art to a proper safety wiring job. The wire has to be routed so that when it is twisted tight, it is in effect pulling the bolt/nut tighter.
 
The correct torque for mains is 75-80 ft lbs. For rods with castellated nuts, 35-40, with self locking, 40-45.
 
You must log in or register to reply here.
Back
Top