Chinese Teapot inscription
It's "鉄鋳". It means "It's made of metal."  鉄 means metal.

They are another kind of (simplified) traditional Chinese characters(铁铸). some people may say they are Japanese kanji, but you know kanji(汉字) are from China. 

Chinese characters have different shape in different period, in different area, such as Hongkong and Taiwan.