Why Are Hardboard Pins Made From Copper?

[hairygrape]

I'm using some hardboard nails at the moment that look like panel pins with a diamond shaped top. They are only 20mm long and may be more appropriately called pins rather than nails. They are either made from copper or copper-plated. Does anyone know why they are made from copper or copper plated for use in hardboard? I wouldn't have thought that hardboard could cause corrosion to a steel panel pin. I also don't understand why these nails have a diamond shaped head when ordinary panel pins can be punched below the surface. Are these types of nails or pins suitable for use in softwood timber moulding too? What about verdigris? Thank you.

[retrocop]

Well they shouldn't rust.

[The Builder]

There's really no need for copper pins with hardboard, Hairy. Steel pins are fine. If discolouring might be a problem, then go for "sheradised".
It's a sort of "galvanising"

Copper pins are often used in hardwoods for a neat, unobtrusive look.
Using them in hardboard, it's essential to drill a pilot hole first, to make then easier to hammer in. They're usually left with the heads flush with the surface.

[TonyV]

Hairy where are you putting hardboard nails into and what you putting up / down, will be easier to give best advice.