All right, i've had a second look at these and i realised these are supposed to be Greek coins due to the greek alphabet.in fact, during the reign of Alexander the Great, the land which we call now "Afghanistan" belonged to the big, Greek empire. The coins pictured here have actually existed and were used during 336-323 BC. That seated old guy with a bird is, for example, a famous design.
It is a fact that these type of coins have been found in the provinces of Afghanistan. However, they would hve been made of silver ( sometimes bronze as well ) but i dont think Iron/steel has been used for making coins ( in that particular era ). I still doubt their originality.