The document describes the Zenith model 913 concrete block making machine. It is ideal for economical mass production of high-quality concrete blocks. The machine produces blocks directly onto the ground in lines and is capable of producing hollow, solid, foundation, and chimney blocks. It has outstanding performance both in open areas and buildings. The machine is equipped with hydraulic systems for easy interchange of moulds and turning of the machine at the end of production lines. More than 6,000 of these machines have been installed worldwide.