Conversion for construction is much more complicated than it appears.
Everything in the National Building Code used to be based on 4 inch modules -- e.g. 16" between studs, 48" X 96" plywood, etc. A "hard conversion" uses 10 cm. modules -- close but not the same. Metric plywood is slightly smaller at 1200 mm X 2400 mm (everything is measured in millimeters, to avoid any need for decimals or fractions). Thicknesses are different too.
Most house builders still use Imperial (I think). The two don't mix. If you use metric plans, you need metric materials -- soft conversions simply aren't practical. (Too many decimals.)
You can get by without a metric hammer though. :-)
I did not know that, thank you.
Am relatively new to the Construction industry.