22 replies to this topic

[Spider]

 

It's that 'foreign' so-called stainless.

 

 

Bhahaha,, the one that rusts,,,,

[AndyR]

What material is an over the counter heli-coil made of? Stainless steel wire. 

 

So therefor in theory should not be used in an alloy casing, however the anodic metal (alloy) is considerably larger than the cathodic (stainless) so should have little to no effect.  Stainless fasteners in alloy casings should be ok (non load situations if not ARP stainless) as long as they are not in a high risk of contact with a salt solution.  If stainless fasterners are used and you are concerned, use a good quality anti-seize paste.  An aluminuim fastener in stainless steel casing would be a very bad idea - the other way round and it should be ok.

 

Andy

[Cooperman]

I think that the Heli-Coils used in alloy aircraft engines are not stainless steel, although I can't remember what the material is.

I don't know whether they are still available, but weren't there phos-bronze Heli-Coil inserts, although I don't think that would be used for aircraft engines.

For most of our classic car applications st. steel should be OK.

[Spider]

There are also rustless steels, which are not technically stainless steel too.

[Cooperman]

There are also rustless steels, which are not technically stainless steel too.

Pity they didn't use this to build Minis  .

[AndyR]

Yeah, for the aircraft industry the correct material heli-coil would be used, but these are generally exotic materials where safety is a higher priority to cost  - and you would have to know what you were ordering.  When ordering a standard heli-coil from a motor factors etc, it will be stainless.

 

Sorry to for delving off topic.

 

Andy

[Fast Ivan]

its horses for courses really; we use a lot of stainless in Oceanography for obvious reasons, 316 being the absolute minimum specification right up to the super duplex.

Titanium and carbon fibre are used as well with the correct increase in cost!!

 

Point is a material is chosen for a variety of its properties for the given application

[Cooperman]

I worked for a while in petro-chemical design and we used huge amounts of stainless. Very expensive stuff.