Dissimilar metals and copper slip

[bazjude2998]

Is it safe to use copper slip when assembling steel into a alloy casting,or is there another product more compatible with dissimilar metals

[ssray]

Yes, it's what I usually use when putting motorcycle exhaust studs back in

[Pastie Bloater]

Yes it's safe to use, but I'd recommend nickel for high temp stuff like exhaust studs etc.
Bear in mind torque specs will be for clean and dry threads (unless otherwise specified like 'lightly oiled' or something) so might need to be reduced to suit. This is more relevant for threading into alloy as the last thing you want is to pull the threads out by over-torqueing it, the risk of which depends on length of engagement, which can vary a lot.

[archie456]

I use this stuff.

As it is silver any excess squeezed out doesn't show and so it looks better on exposed casings e.g. on a motorbike.

[markcoznottz]

Pastie Bloater said:

Yes it's safe to use, but I'd recommend nickel for high temp stuff like exhaust studs etc.
Bear in mind torque specs will be for clean and dry threads (unless otherwise specified like 'lightly oiled' or something) so might need to be reduced to suit. This is more relevant for threading into alloy as the last thing you want is to pull the threads out by over-torqueing it, the risk of which depends on length of engagement, which can vary a lot.

Copa slip is great stuff. Saw a mechanic using normal grease on spark plug threads I asked why he said, ‘ well it’s the same’. It was lost in him that c-s is anti seize compound, for dissimilar metals, whereas grease is a lubricant. I’m not surprised by what I see nowadays.