Question on Jet Nuts - Use Washers?

[Tidybuoy]

I'm using Jet nuts (or J-Nuts) on my PMO's because standard M8 nuts won't fit. When I bought these, it said self locking, can be used as intake or exhaust. However, the nuts screw on very easily all the way down to the base.

My question: Do these somehow tighten & lock when you torque them down or should I be using a lock washer? There's not much room left for a washer (of any kind).

My photo shows the nuts hand tightened only.

[The cap'n]

I looked on their web page, and it says the nut is deformed for locking purposes. Most nuts of this design are one time use only.

The Cap'n

[KTL]

If they screw right down with no resistance then they're not jet nuts. Jet nuts have an oval hole at the top because they've been mechanically smushed a small amount in order to slightly interfere with the stud threads.

However, your studs appear they are not long enough to engage the smushed threads in the top of the jet nut.

Picture of jet nut courtesy of the good guys at Pegasus Auto Racing Supply

[eastbay]

You need shorter nuts or longer studs, general rule of engineering is the stud (or bolt) should extend past the nut by a minimum of 50% of the diameter of the stud/bolt

[Tidybuoy]

Originally Posted by eastbay

You need shorter nuts or longer studs, general rule of engineering is the stud (or bolt) should extend past the nut by a minimum of 50% of the diameter of the stud/bolt

I'm using the studs that came with the PMO's. I would think that they would provide the right size. However, I have not torqued them down. Also, I was shorted the nuts that were supposed to come with the PMO's so maybe they were of the shorter variety. I may have to do some more shopping this weekend.