Nail type for Plain Clay Tiles

[BadgerBadger]

Could anyone confirm the right/best/usual nail material for fixing plain clay tiles please?

 

I think my googling is guiding me towards aluminium, but not too commonly available so do many roofers just use galvanised?  Copper seems superior and common with slates, but excessive/expensive for plain clay tiles with nibs?

[Canski]

Aluminium for me. I never had a problem obtaining them.