The hardness of iron

Answer 1

It's actually a rather difficult question to answer as iron can be forged in a number of different ways, each giving a different hardness. I've attached a link to a site giving different hardness values for some treatments of grey iron.

Answer 2

Hardness is measured in three types viz., Moh's hardness, Brinnel hardness and Vicker' hardness.

Hardness of Iron is,

1) Moh's Hardness-4,

2) Brinnel Hardness-490 Mpa,

3) Vicker's Hardness-608 Mpa