Brass nuts for exhaust system

[RimfireJim]

The ORD 9 for the M38 calls out 3/8"-24NF and 5/16"-24NF brass self-locking nuts for the exhaust system - brass to keep them from corrosion welding to the bolts. I can find standard (non-self-locking) nuts in these sizes, but can't find the self-locking version. So, three questions:
1. Anyone have a source for the spec'd nuts?
2. Could I turn a standard nut into a self-locker by upsetting some material?
3. Are self-locking nuts really required for civilian use?

Inquiring minds want to know . . .

-Jim

[wesk]

Self locking nuts are required civvy or military. The exhaust manifold if working loose will rapidly erode the gasket and then the exhaust will start eroding the material from the manifold's face and the block face. If this is allowed to continue for long periods or re-occur often due to loose hardware you will eventually reach a point that the surfaces can no longer be machined completely flat and true. John at Midwest has the nuts as does AJP, deBella and I believe Rapco.

The brass nut is required for correctness in restoration. Mine gets stainless steel all metal self locking nuts. As a rule the brass are only good for one use.

[OKCM38CDN]

John Bizal at Midwest Military has them, also several other vendors...

They are not cheap... $3.75 each...

I bought 7 back in the day and put them on the manifold, then on the rest of the exhaust i put regular brass nuts ... not 100% correct but in the spirit of it... I also used lock washers on the regular exhaust pipes...

Hope this helps..

[ocwd]

I bought a couple from Midwest a few months ago for my exhaust manifold. I just used stainless steel nuts and bolts on the center exhaust and muffler as suggested by someone on this site. Those are tucked under the Jeep any way.

[idiocrates]

I found....or rather convinced the counter guy to let me look in their brass hardware bins....all brass self-locking nuts at O'Reilly's Auto Parts. They had 'em.....they just didn't know it.

[RimfireJim]

Thanks for the answers, guys. You made a very convincing case, Wes - self-locking it is, then. I had searched AJP and deBella's sites under "Exhaust" but didn't see the nuts listed. Midwest's site is too time consuming to search unless yer desperate. Stainless is fine for our project, and probably easier to find. I'll check at the local parts stores. (Our experience when searching for an inverted flare adapter fitting at O'Reilly's was just like idiocrates' with the brass nuts.) McMaster-Carr also has stainless nuts in both the Flexloc style (at $3.14 each!) and the distorted thread style ($6.76/10).
-Jim

[STXM38A1]

Look about half way down the page on the right-hand side for Midwest's
http://www.midwestmilitary.net/adpage3.html

[DJ]

Brent Mullins has them in the new Supply Line