Why Do Masonry Drill Bits Have a Blob Of Paint on the End?
The cutting edge of masonry bits is formed from a chip of tungsten carbide that is brazed onto the end of the steel rod. Tungsten carbide is extremely hard to enable it to resist abrasion but is easily chipped by impacts. The paint does help to provide a cushion that reduces damage in transport. Wood bits are made from hardened steel that is no-where near as brittle as carbide.
