A drill-down on making great holes

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One thing penetrating into another is always made easier by first creating a hole.

No matter how skilled, how mighty, or how overwhelmingly powerful the athlete carrying the ball is in the sport of professional football, his success in progressing past the line of scrimmage will correlate directly with the size of the hole created.

If the 300-pound offensive lineman creating this hole was successful in separating the angry bunch of 300-pound defensive linemen in the way, then the skilled ball carrier passes through with minimal discomfort.

If the offensive lineman fails to create a hole, either due to lack of skill, poor timing, or the fact a few individuals are somewhat disgruntled by recent contract negotiations, then the ball carrier will certainly be facing a whole lot of hurt.

Most nails and screws will penetrate wood. There are self-tapping screws designed to drill and pierce through steel. There are even nails that can be hammered into solid concrete.

However, it’s always easier when there’s a hole created first.

Let’s look at some of the things we can use to create holes. Things to realize; steel drill bits will cut through wood, but wood bits won’t cut through steel, while concrete bits will only really cut through concrete.

That being said, with enough weight or pressure, a drill bit could be forced through just about anything, just like a grand piano could be forced through the mail slot of a front door, but it wouldn’t be pretty.

To keep things easy, and pretty, we use the proper designated drill bit for the task at hand.

Essentially, small holes of 3/16” or less, often used to pre-drill wood in order to accept a nail or screw, are effectively done with a steel drilling bit.

Holes required to be anywhere from a quarter-inch to 1.5 inches in diameter are best drilled with a spade bit, which has a flat head, similar to a canoe paddle. Using a steel bit for these sized holes will work, but you’ll be forfeiting accuracy. A steel bit will move around a little on the surface before it bites down into the wood. Plus, the hole will be frayed at the sides, due to the steel bit lacking the extended, cutting edges found on a typical spade bit.

Anything larger than 1.5 inches would require a hole-saw, which is a cylinder-shaped cutting tool. Hole-saws are two component drilling tools, requiring a centre bit, referred to as a “mandrel,” to start the hole. The mandrel further guides the circular hole-saw into the wood. If this is your first hole-saw purchase, don’t forget to buy both components. Generally, one mandrel will service a number of various hole-saw diameters.

However, not all centering mandrels match all hole-saws. So, be sure to test-fit your existing mandrel with the newer hole-saw before leaving the building supply centre.

Note to self: drilling with larger spade bits and any sized hole-saw bit is like playing catch with a football, best done using two hands. If your drill doesn’t have an extended arm to place a second, steadying hand, definitely consider ordering one of these components for your specific brand of drill. Otherwise, keep two hands firmly on the trigger shaft.

Spade bits and hole-saws will sometimes jamb in the wood. If that happens, and you’ve only got one hand on the drill, the sudden twist is going to leave your wrist looking and feeling like a strand of cooked spaghetti.

Next, be wary of purchasing just any spade bit. Some spade bits have regular tips, others a full-thread tip. The full-thread bit option effectively draws the spade bit blades into the wood, making this bit very aggressive— which is fine if you’re an electrician with 1,000 holes to drill. Otherwise, I prefer the gentle push, draw back (which helps clear the hole of cuttings) then push forward strategy of a regular spade bit.

Next week we’ll have more on creating holes.

Good building.

As published by the Standard-Freeholder
Handyman's Hints Standard-Freeholder Cornwall Ontario by Chris Emard

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