Woodworking Tools
A Primer for Drills and Bits | Also See Planes, Jointers and Planers
A drill is a tool with a sharp point and cutting edges for making holes in hard materials (usually rotating rapidly or by repeated blows) . I remember back when in my HS Shop days, anyone asking for a "drill bit" would get the 30 second lecture.
"And you want this for what?" the teacher would ask. "Gotta drill a hole in some sheet metal, Mr. C." would be a likely reply. "A drill and a bit are two different things son," He'd start. "A bit goes in an Auger" and a twist drill goes in a drill," is how he would end the conversation. His wisdom was lost on most of us, but we did learn how NOT to ask for a tool. I pass along this bit of info because when we refer to "bits" and "drills" NOT drill bits and now you know why.
Bits & Drills are made from various materials. So its not just matching tool with purpose, it's matching your requirement with the tool. Steel bits and drills are inexpensive and work well for boring in softwood. However, steel bits dull quickly in hardwoods. So you have to ask your self, "would I rather burn through ten cheap ones or just pay the bucks for one that may last 20 years?"
If the answer is pay a little more, than the mateials to look for are:
- High-Speed Steel (HSS): Harder than steel and stay sharper longer.
- Titanium Coated: Cost slightly more than HSS, but they are tougher and stay sharp longer than HSS or steel.
- Carbide-Tipped: Moving up in price now, but they stay sharp much longer than steel, high-speed steel or titanium bits.
- Cobalt: Big bucks. But extremely hard. They dissipate heat quickly and most commonly used for boring in stainless steel and other metals, so not really a woodworking tool.
The following is a "generalized" list of drills and bits that are commonly used in woodworking.
Twist Drill
General purpose tool for drilling in wood, plastic and light metal. Sizes generally range from 1/64" to 1/2" diamater. Available in metric sizes.
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Brad Point Bit
Used for boring in wood. Has high points (or brads) for easier positioning and accurate boring. Has extra-wide flutes for removing scrap. Sizes generally range from 1/8" to 1" diameter. Available in metric sizes.
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Spade Bit or Paddle Drill
Used for boring large diameter holes in wood. Sizes range from 1/4" to 1 1/2" in diameter. Available in metric sizes.
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Adjustble Spade Bit
Used for boring large diameter holes in wood. The adjustable blade allows multi-diameter holes
from 3/4" to 3". Available in metric sizes.
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Auger Bit
Used for boring in wood. Coarse screw end for quick drilling. Has large flutes for chip removal. Used in an Auger. Available in metric sizes.
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Hole Saw
Used to bore large diameter holes in wood and light metal. Sizes range from 1/2" to 6" in diameter. Available in metric sizes.
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Forstner Bit
Used to bore "flat-bottomed" holes in wood. Sizes range from 1/4" to 2" diameter. Available in Metric sizes. |
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Counterbore, Pilot and Countersink Bit
Used to dril pilot, countersink and counterbore holes in one step. Some have replaceable and interchangeable pilot drills. Others have adjustments for depth of countersink. |
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