Drill bits are attached to power drills to make holes. drill bits are made of because they’re hard and resistant to corrosion. the bodies and handles of power drills are made of because they’re good insulators.

Drill bits are attached to power drills to make holes. Drill bits are made of carbon-steel because they’re hard and resistant to corrosion. However, it is not only limited to carbon-steel. There are also other materials that are used for drill bits such as high speed steel, titanium coated steel and the like. The bodies and handles of power drills are made of polyethylene because they’re good insulators. 

You would be correct, boiling water does disinfect contamination.    the property of disinfecting means to kill  germs, bacteria and other pathogens or contamination  that might cause an infection or cause a person to become sickly. a couple methods of disinfecting are using soap, other cleaning supplies or by simply "boiling" the contaminate.  the reason why boiling water disinfects certain attributes is because some cells cannot survive the heat and pressure.