I was on Bel-Metric the other day an ordered up some of these. Got them today and tried them out. Rather unique in size. They have a 17mm flange and a 10mm nut. The flange just about covers the entire mounting oval of the heat exchanger and the 10 mm head is alot easier to get the socket in to tighten up. The original 13mm can be a real battle royal even with a wobble socket. $10.32 for the set.

Thanks Mark...that's very interesting....BelMetric is great for all these things

Is the hole ovaled like the other copper clad ones? I never trusted the torque values on those. I'm on the stud nut 'fence' after reading a "double nut and anti-seize" tidbit Len thru out in a thread.

Hole is ovaled out and lock down really tight. I took them back off and the stud came with them. Going to have to put a little loctite on the studs.

These should be cut off, for removal, as they will gall on the steel stud.

Use Milk of Magnesia on the nuts to keep them from seizing or galling on removal?

Zach

I use those for my audi turbo manifold. A bit of a paint to start with the ovaled hole but they so far have held well. I know I have more abuse on them than what a typical type 4 would with the heat the turbo generates as well as the weight of what essentially is my manifold, large turbo, and whole exhaust.

I used those once. Won't do it again! Pulled 6 of 8 studs out of the head removing heat exchanger! Proper repair cost $300 !

I like the copper jacketed, small OD nuts that ARE NOT locking. I've not had my exhaust loosen up, but I have had to put studs back in after those little oval bastards grabbed on and wouldn't let go.

Ok, looks like a $11 experiment went South.

https://www.belmetric.com/hex-with-flange-c...-nut-p-189.html

Got a source, Belmetric maybe ?

Look at my post that is literally above yours.

Wow howd I miss that!! Thanks.

I use these on my Audi and VWs.

exhaust nuts

What is the 'locking' feature on those from AC.net?

I always run a 8X125 tap through before I use them . keeps from pulling the studs out