I think there's a bit of misunderstanding here...
Nickel plating is part of the typical chrome plating job. The old hotrodder's bit about "triple chrome" means copper, nickel, then chrome plate. Think of it as the chrome being the primer, the nickel being the color, and the chrome being the clearcoat.
And that's a valid analogy: The copper adheres best to steel, and in effect 'seals' the surface. Nickel provides the "color", and a good deal of the strength of the coating, the only problem being that nickel has a faint yellowish cast to it. Chrome provides a thin, even harder layer to protect the nickel, and gives it a brighter, bluish cast which looks more appealing. Nickel can also tarnish, so the chrome essentially 'seals' it to preserve the appearance.
One could apply chrome directly, but in order to get a similar appearance, you have to apply a lot of it- and of the three materials, the chromium is by far the most expensive. Also, applying that much chrome is power intensive, requiring more energy applied than the three layers separately.
Still, lots of tools use just a wash of nickel for some measure of anticorrosion, and a lot of those use electroless. "Triple chrome" processes rarely do, however, as EN has to "auto catalyze"- the chemical reaction starts easily and automatically on steel, but over copper, you have to in effect "jump start" it, usually by somehow having iron/steel in contact with the copper.
And even that isn't ideal, as the reaction then has to "spread out" from the contact points, which leads to varying thicknesses of plate, and/or unplated areas. Standard electro-deposited nickel, in those cases, is easier to 'start' and produces a more even finish.
Doc.
