As brad point bits are mainly used with wood, they do not usually require any form of coating for protection. However, if you are prepared to spend a little more money on a bit with a coating, you’ll be rewarded with a degree of resistance to corrosion.
For more information on each of the coatings that follow, see: What are drill bits coated with?
Titanium nitride
Titanium nitride is corrosion resistant and helps to prevent sharp edges from wearing down. It is gold in colour, and sometimes represented by its chemical formula, TiN.
Black oxide
Black oxide is an iron-based compound that is partially resistant to corrosion and frequently used on metal tools.
It is relatively cheap and will not add a huge amount to the cost of your bits.
