Difference Between Wood & Steel Drill Bits

Most drill bits designed for cutting through steel can also be used to cut holes in wood. However, there are some important differences in drill bit design and a few bits that are unique to working wood.

Materials

High-speed steel is the most common material used in making either steel-boring or wood-boring drill bits. Bits are also made from titanium, tungsten carbide and cobalt, all of which work far better on tougher materials such as stainless steel or cast iron. These drill bits are not only stronger but will last much longer and are appropriate for boring into wood, too.

Point Angle

The drill bit tip differs depending on the softness of the material to be drilled. The tip angle or the sharpness of the bit's point should be larger for boring into harder materials such as steel and sharper for boring into softer materials such as wood.

Twist Bits

Twist bits have fluted, spiraled channels to remove waste material from the bore. Wood drill bits sometimes have deeper flutes that remove this material more efficiently than a steel drill bit would.

Special Wood Bits

Auger bits and spade bits are two common specialty wood drill bits designed for specific purposes in wood boring. Auger bits have deep flutes for fast chip removal and are made to quickly drill large, deep holes. Spade bits have a very sharp point and a wide blade meant to drill large holes.

Brad Points

Some wood bits have a brad point, which is a short, thin extension that bites into the wood at the precise location desired.

References

• Toolnewz.com: Metal Drill Bits
• Toolguy.com: Metal Drill Bits -- Wood Drill Bits -- Drill Bits
• Oneprojectcloser.com: Wood Drill Bit Reference