Q. What material is used to make a honing machine?

Answer

It's possible that the honing machine is made up of an abrasive diamond boring bar. This bar might be constructed from a sintered sleeve with abrasive implanted in it or from a soft cast iron sleeve that is extensible that is permanently coated with 120/100 grit natural diamond abrasive. Both of these options are possibilities. Because diamond sleeves wear out over time, the tool may expand to accommodate the wear.