Chilled-cast tiles for lining of esp. a concrete mixer trough has aperture in back with round thread, cast in negative mold with zircon sand section for thread, for higher quality

摘要

The tile (10) has an aperture (12) in the back, for fastening to the inside wall of a mixer trough. A round thread (14) is cats into the peripheral wall of the aperture. The tile is cast in a negative mold, and the mold section for casting the aperture is of zircon sand, is without release agent, and has a round thread. The sand has a grain size of less than 02mm diameter.