Tilkal

Tilkal was a metal crafted by the Vala Aulë according to the early version of the legendarium in The Book of Lost Tales. It was used in the chain Angaino that bound Melko:

The name tilkal is an acronym from the Qenya names of the metals mentioned above:
tambe = "copper, bronze"
ilsa = "silver"
latúken = "tin"
kanu = "lead"
anga = "iron"
laure = "gold"