Pipe Manufacture
Hardie Pipe is manufactured using the mazza process. This involves building up a number of thin laminations of a slurried mix of Portland cement, ground sand, cellulose fiber and water, onto a steel mandrel under high pressure. The use of a polished mandrel ensures a very smooth pipe bore and a consistent internal diameter across the various pipe strength classes.

When the desired wall thickness is achieved, the mandrel is removed and the pipe is initially cured in a steam chest. The final curing, which is done in a high pressure steam autoclave, changes the chemical structure of the cement/silica matrix producing a more chemically resistant and stronger material. The pipe ends are then machined on a lathe to produce the various joint profiles.