Antiseizing stainless steel for helical inserts

[Lindsay]

Viewing McMaster-Carr to compare key-locking thread inserts and helical style.
Found antiseizing, 18-8 stainless steel for helical inserts.

Anybody have experience with antiseizing helical inserts?

Stainless Steel Threaded Insert Material Types:

*18-8 Stainless Steel Offers excellent corrosion resistance; it may be mildly magnetic.

*Antiseizing 18-8 Stainless Steel Lubricated for gall resistance. Galling, also called seizing, is when two metals stick together and cannot be easily loosened. A combination of nonmagnetic 18-8 stainless steel, manganese, nitrogen, and silicon reduces friction to minimize wear with no additional plating or coating required. Compatible with stainless steel fasteners.

*316 Stainless Steel Has better corrosion resistance than 18-8 stainless steel because it contains molybdenum, which increases resistance to chlorides and sulfates.

NOTE:
I placed this discussion in exhaust system. Consider antiseizing helical inserts to repair a SPRINT exhaust manifold. Don't think there is enought edge distance at "exhaust pipe header flange" to use key locking inserts. Key-locking insert for M8 x 1.25, requires M12 or 1/2-13 tap hole to install insert.

[GTJIM]

HeliCoils are bad news for cast iron exhaust manifolds as they tend to unwind when the bolt is removed some time later.
Just drill the stripped holes to 5/16" (8mm is very close) and tap the holes 3/8" UNC so you can use 3/8" stainless steel studs. The larger and coarser UNC thread is much stronger in cast iron. With studs the thread does not get stressed so much and may never need fixing again.

[opelbits]

Although I have not had any problems with helicoils in cast iron, if you can save as much cast iron meat as possible, do it.

And use brass nuts, not steel or stainless. The brass won't seize and if there is a problem, it is much, much easier to drill it off.

[jtb]

When I had aluminum heads with cast iron exhaust manifolds, I had lots of problems with the exhaust bolts ripping out the threads. After using helicoils, I found that liberal amounts of Nev-R-Seize helped prevent galvanic corrosion.

HTH,

jtb

[namba209]

I've put this info out here before, but it seems appropriate to do it again. For all exhaust bolts, got to your local airport and get the same anit-sieze compound they use to put the spark plugs in the aluminum heads. It may have a military specification "MIL-T-555" This compound has a two-fold application, first and foremost it allows the plugs to be removed without stripping the threads. Secondly, it is graphite based and helps in making a ground from the plug to the engine head. And because it is designed to be used on aircraft spark plugs, it will withstand the heat. Every bolt or nut installed in Willit? has the first 1/4" of threads applied with this compound.

[Lindsay]

http://www.opelgt.com/rp/showproduct...oduct/26/cat/3

I am aware of these studs with copper nuts for use with OPEL exhaust header. Still need to find time to remove two broken studs in my Sprint exhaust manifold. Read about soaking in COKE for several days/ week. Then, use high heat and apply candle wax. Once I remove broken studs, will evaluate either M8 or 3/8-16 size replacement. Need to purchase specific anti-seize compound that Ron recommended. THANKS ALL!

[oldopelguy]

The VW shops all sell a set of 8 copper or brass nuts for the exhaust studs in the standard 8mm thread pitch but with 11mm heads instead of the usual 13mm heads for the tight clearances around big VW air-cooled headers. Dirt cheap, a set is under $5, and getting a 11mm socket in there is a whole lot easier than a 13mm one.

[namba209]

Originally Posted by Lindsay http://www.opelgt.com/rp/showproduct...oduct/26/cat/3 Need to purchase specific anti-seize compound that Ron recommended. THANKS ALL!

Lindsay, take a run out to Montgomery Field and check out some of the maintenance supply shops. Or if that's too far south, try Palomar Airport up north.