Page 44 - How It Works - Book Of Amazing Answers To Curious Questions, Volume 05-15

Which drill bit

should you use?

Learn why selecting the correct drill bit lets
you make the right hole in the right place

udimentary drills were invented by early This highlights the importance of using the Certain geometric characteristics play a role in
humans so they could bore holes in correct drill bit, which is where the real how drill bits cut through a material. The spiral,
Rmaterials. These days, the ability to drill technological advancements lie. Today there is a or rate of twist, is responsible for moving the
provides society with a range of benefits, from plethora of drill bits on the market in a variety of drilled material from the hole and is varied
accessing petroleum to curing toothache. The shapes and sizes. Most have either a tapered or depending on the required cutting speed. The
technology behind household drills is very sharpened end that cuts away material and an material to be drilled determines the point angle,
simple in design. Squeezing the trigger initiates auger (a spiral screw thread), that removes the which is the angle formed at the bit’s tip. Harder
an electric motor, causing the chuck to spin the drilled material from the hole. Numerous materials need a larger angle in order to drill
drill bit, which cuts into the target material. speciality drill bits also exist. These have a them, while softer materials need a sharper
Despite the simple design, inefficient drilling unique design and specialised function, such as angle. It’s vital the correct one is used; this will
can still create problems, potentially damaging the cone drill bit, which can drill different- reduce the risk of the drilled hole being uneven
the material or the user in the process. diameter holes in thin materials. or in the wrong location.

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HSS-Rolled The most common kind of drill bit, ideal for use on plastic, wood and metal. Spur auger Similar in function to spade drill bits, they leave neater holes and require less torque to spin, hence they are a popular choice for hand-powered drills. Brad-Point This drill bit offers precise drilling in all types of wood, due to its centring tip. Flat/Spade With this drill bit it’s possible to drill cleanly and accurately through wood. They are also easy to sharpen and inexpen

44 How It Works