Tip #25
Everything You Want To Know About Drilling (continued)
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Special Purpose Drill Bits

In addition to the most common types of bits listed above, there is also a large variety of unique bits that make easy work of certain specialized operations. While most of these are readily available at your local home center or hardware store, others are a bit more difficult to find.

Long Bits can be a real “life-saver” when you need to drill deep holes or holes through extremely thick pieces of stock. 12" long twist-style bits are easy to find...but long brad points are another story. Although the latter are available in lengths of 10", 12" and even 18", you'll have to do some searching to find a source.

Screw Drills

Screw Drills are unique, “triple-function” bits that drill a tapered pilot hole for the screw threads, a countersink for the screw head and (if you prefer) a counterbore to accept a wooden plug that's glued into place to hide the screw in certain types of projects. They're available individually for screw sizes from #5 through #12...or in complete sets and most are fully adjustable for screw length as well as countersink and counterbore depth. They're real time-savers and are well worth the investment if you use a lot of screws to hold your projects together. They work equally well in a drill press or portable electric drill.

If you're not using Screw Drills to bore pilot holes, counterbores and countersinks, it's important that you know what size of hole to drill for which sized screw. Here's a handy table that provides that valuable information.

Vix Bits

Vix Bits are the best choice for ensuring that your hardware mounting screw holes match-up exactly on-center with the holes in the hardware. Just hold your hardware in position on the workpiece and use your portable electric drill to bore the mounting holes. Each bit features a spring-loaded plunger with a tapered end that matches the countersink in your hinge or other piece of hardware. As you push your bit into the workpiece, the plunger end keeps your hole perfectly on-center. Pretty nifty!

Hole Saws

Hole Saws are the best choice for cutting large diameter holes. They're readily available at most home centers and hardware stores in sizes up to about 3". They feature a center pilot drill to help you locate the center of your hole and keep it on-target throughout the boring process. As a result, they can be used in a drill press or in a portable electric drill. They're also available in standard (shallow) or deep boring models that will go through 2" or thicker lumber in a single pass -- and with regular steel sawing teeth or with carbide teeth for boring through tough woods and non-ferrous metals.

Plastic Bits

Plastic Bits resemble standard twist-style bits...except they have a steeper, 60-degree point that provides a larger cutting lip for more surface area and improved performance when cutting through all types of plastics. This steeper point minimizes the chances of grabbing and chipping during the drilling process.

Glass Bits

Glass Bits are made of solid carbide and feature a spear-point shaped tip that will bore a super smooth hole through all types of glass. They should be used exclusively in a drill press at slow speeds. For best results, build a small, circular “dam” around the hole location with plumber's putty (stainless putty). Pour in a small amount of turpentine and start drilling. Feed the bit very slowly into the hole. Take your time and don't rush the process.

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