as we know, the barrel forms the main part of darts. nowadays, tungsten-based tungsten alloy billets are widely used as the standard tungsten barrels material, for it has a specific gravity of 19.3(20), making it a very dense material with small volume. besides, it has superior wearing resistance, well machinability, etc.

Write the above sentence using proper case.
As we know, the barrel forms the main part of darts. Nowadays, tungsten-based tungsten alloy billets are widely used as the standard tungsten barrels material, for it has a specific gravity of 19.3(20), making it a very dense material with small volume. Besides, it has superior wearing resistance, well machinability, etc.