That looks like Babbitt to me. I buy it today and it comes in ignots exactly like these. It has a low melting point and is used to make bearings in various types of rotating equipment like pumps and gear drives in the oilfield and many other applications I am sure. It is melted and poured around a shaft where a housing contains all the material and it molds into a bearing as it cools down.
Paul is correct. Fry Metals was a company that made various types of babbitt for bearings of all uses.
