Q: Which is better; cobalt, titanium or black oxide for drill bits? By better I mean will stay sharp longer when drilling wood, metal studs, drywall etc. …
A: The answer depends on the materials being drilled. Here’s a general breakdown:
Titanium drill bits offer the best durability and speed for general purpose drilling applications. They’re best for cutting holes into metal and work equally well in wood and plastic drilling. Use in steel, copper, aluminum, brass, oak, maple, MDF, pine, PVC, polycarbonate, acrylic, ABS, nylon, composite materials and common stainless steel.
Cobalt drill bits offer the best heat-resistance and a rigid thick web design for drilling in extremely hard and abrasive materials such as treated stainless steel (precipitation-hardened), cast iron and titanium.
Black oxide bits offer superior durability, speed and selection for most general purpose applications. They’re best for cutting holes into metal and work equally well in wood and plastic drilling. Use in steel, copper, aluminum, brass, oak, maple, MDF, pine, PVC, polycarbonate, acrylic, ABS, nylon and composite materials. (Information courtesy Bosch Power Tools, www.boschtools.com)