whats the deal on castelated nuts on exhaust flanges bolts if...

[Nacho-RT74]

bolts are not with with cotter pins hole provision

( if they should have them of course )

http://www.ebay.com/itm/64-74-Mopar-340-383-440-Correct-Exhaust-Pipe-Bolt-Set-/400249920178?pt=Vintage_Car_Truck_Parts_Accessories&vxp=mtr&hash=item5d30c11ab2

or... are the nuts conical and castelated just spread out as far is being bolted making pressure against the bolt thread ?

[bobs66440]

I think they are just lock nuts. Like you say, the nut is probably crushed in a little at the top to keep pressure on the threads.

[Nacho-RT74]

ok, theeeen, SOMETHING IS WRONG ON THIS SET I got, because I can thread in the nuts into the bolts up to the top actually fairly easy with hands

[bobs66440]

ok, theeeen, SOMETHING IS WRONG ON THIS SET I got, because I can thread in the nuts into the bolts up to the top actually fairly easy with hands

Hmmm. Good question. Maybe call the manufacturer?

[A383Wing]

they are supposed to be slightly smaller at the top so they crimp when put on...

Bryan

[gtx6970]

I think they are just lock nuts. Like you say, the nut is probably crushed in a little at the top to keep pressure on the threads.

They are not lock nuts, never were -  just a castellated nut .
WHY,??  I have no idea
It's just  what mopar used back then

[bill440rt]

Years ago I ended up making some out of stainless steel nuts & used a hacksaw blade to cut the slots. I couldn't find replacements anywhere.

[maxwellwedge]

Marsden Nuts

[bobs66440]

Marsden Nuts

I found this description:
The bottom of the nut is relieved in the center, leaving a ring at the outside edge. When the nut is tightened down against this ring it wants to close up the slots in the upper edge of the nut. The effect is that that the upper area of the nut will grip the stud tightly.

[maxwellwedge]

That's right - That is what was on factory exhaust. Ever try to get one off? A lot will fight you all the way.