The Ins and Outs of Screws and Screwing
When you need to do some screwing, there are a number of things to take into account: drive, size, head, the hole, and, of course, the tool. Get your minds out of the gutter, ladies. Not that kind of screwing. I’m talking about metal fasteners that hold things together. Jeez.
The most important thing you need to know to find the right screw is how to read. And not because you’re going to a nasty chat room! Because you have to read the boxes the screws come in to find out what they’re for. If you’re screwing into drywall, get drywall screws. If you’re screwing outdoors, you’re a risk taker – but don’t risk rust. Use screws that have an exterior rating and won’t rust. If you’re screwing wood, you guessed it, wood screws. “Is that it?” you’re thinking. “Read the box?” Okay, I’ll share some more juicy details.
You can’t screw without the drive. And for this, you don’t need Viagra. You know most of these, I’m sure:
Slot or Flat – driven by a flat-blade screwdriver, butter knife, edge of a spoon…
Phillips – “+” shaped hole designed to piss you off because all you have handy is a butter knife or the edge of a spoon. Cool off, then go out and buy a Phillips head screwdriver
Square or Robertson – those irritating screws that come with Ikea furniture and make you use that L-shaped “wrench” that rips up your hand so you can’t even hold a butter knife or a spoon
For proper screwing, size matters – no matter what anyone tells you. Screws come in lengths ranging from ¼ inch to 4 inches or longer. To pick the right length, make sure the screw is long enough to fully penetrate both items being fastened but not so long that it goes right through. Duh. The shank diameter – critical for good screwing– is called the gauge and ranges from 0 to 24. Diameter increases by about 1/64 inch for each number you go up in gauge. As a rule of thumb, if the items you’re screwing are thin, use a smaller gauge, if they’re thick, you can use a higher gauge.
The head is a significant part of the screw- There are dozens of kinds of heads; bugle head, pan head, trim head, washer head. But the three main heads are:
Flat – The most useful head, sits flush with the surface or can be countersunk and hidden with wood putty or plugs
Round – Nice for a decorative effect because it sticks out above the surface in a semi-sphere, and is also frequently used for plumbing and metalwork
Oval – Primarily used to install cabinet hinges and other hardware because the shape fits snugly in the machined hole.
There’s no screwing without a hole- To make the driving easier, you should drill a pilot hole The pilot hole should be about as deep as 2/3 of the screw length, and just less than the diameter of the core of the screw.
When fastening something to brick, concrete or other masonry
When working with hardwoods that won’t allow an easy drive or could split from the pressure
When working close to the edge of your material so it doesn’t splinter
Screwing success depends on an effective tool- It’s nearly always best to use a power drill or power driver to drive the screw. Just be careful that you don’t strip the head, which means make a total mess of the slot so you can’t drive the screw in further or take it out. We’ve all done it. If you’re using decorative brass screws, always use a hand driver because brass is so soft, you’re sure to screw it up with a power driver. Drill a pilot hole and lean into it, girls.
This is about as much as I can tell you about screws and screwing while maintaining my wholesome image and G-rating. If you need to know any more, ask Dr. Ruth.
Question from a Dishmag Reader
Is there a numbering system or any logical way to relate the size of the drill bit to the best possible size of a Pilot hole for a certain Screw? I can’t seem to figure it out, except by looking and guessing. Is there a better way?
I match the pilot hole and screw width by eye. If you look at the screw from the pointy side you can see the diameter of the actual core of the screw (not including the threads). That's how big to make the pilot hole. You don't want to make the hole too big because the screw will not hold. If necessary, err on the side of making the hole too small. If it's too hard to drive or the wood starts to splinter (but try to catch this before it happens), unscrew and make the hole bigger with the next size drill bit.
If you have any home repair questions for Sarit, please e-mail them to email@example.com. To find out more about the wonderful Sarit Catz, visit her website at www.saritcatz.com