Nails vs. Screws vs. Bolts

Lots of questions arise when trying to decide between three of the most common items used in fastening, attaching, and securing – screws, nails, and bolts. When selecting fasteners, you will want to first consider the nature of the job and the materials that are involved. A thumbtack is fine for pinning paper to a corkboard, for example, but it won’t be strong enough to hold up a picture frame and it will not have the power to penetrate a solid oak board.

All three of these categories of fasteners are sold in many different lengths and gauges, or thicknesses. They are also available in a variety of different types of metal. Some metals are more corrosion-resistant, for instance, while others are less expensive but could rust if exposed to moisture or the outdoor elements. Gauge, length, and material will be determined by the specific application you have in mind, and can also influence the price. By taking a look at the strengths and weaknesses of each category of fastener, and knowing what kinds of general applications each one is best suited for, you’ll be able to make the correct choice every time.

Nails vs. Screws

Nails – whether hammered by hand or shot out of a nail gun – are a good all-around choice when performing basic construction and the components are not subject to strong force or pressure. There are some unique considerations when selecting nails versus screws, as explained below:

• Nails are less expensive than screws, and are faster to use. Two or four whacks from a good hammer and you can drive a nail all the way into a pine board, whereas installing a screw takes a little more time.

• Nails are rather flexible, which is why if you hit one with a hammer at a bad angle it will bend. Screws, on the other hand, don’t have that flexibility. While a nail may gradually bend over before failing to support whatever you built with it, a screw subjected to too much weight or pressure will likely just snap in two, abruptly and unexpectedly.

• If you accidentally bend a nail by hitting it at the wrong angle, you may be able to pummel it straight again and reuse it. You cannot do that with screws, which are more brittle under than kind of pressure.

• When forces like gravity and weight bear down on a nail, it has less strength to withstand that pressure. It will bend until its holding power fails, or it could just snap off if the force exerted against it is powerful enough.

What does this all mean for you? Well, if you are going to hang heavy cabinetry on your kitchen wall or erect bookshelves in your den, definitely do not use nails. They will lay over, flex, and bend, while your cabinets or heavy shelving collapse. If you are putting up 2 x 4 studs to create a wall, nails should work just fine. Your home is probably built with nailed studs, and the flooring may have been nailed into place, as well as the sheetrock or wood that comprises the walls.

If you are attaching molding around the edges of your floor, or tacking decorative molding around the frame of a doorway, nails should be fine. Finishing nails, which have a very tiny head, are perfect for many decorative applications, because you can hammer them flush or even below the level of the surface you are penetrating with the nails. Then you can use wood filler or a similar product to cover the spot where the nail went in, and the whole procedure becomes practically invisible to the naked eye.

Screws, on the other hand, work best when the application involves forces of weight, pressure, or gravity. Because they are shaped like a corkscrew, this allows them to bore into the wood and grip it in the little gaps between the spirals of the screw. With that kind of bite, it is hard for the wood or other material to wiggle away, whereas it is much easier for wood or other material to slide off of a smooth-surfaced nail, when subjected to extreme weight or any pulling and pushing pressure.

Bolts

Bolts are especially handy when you want to have a project that can later be easily taken apart or disassembled. Bunks beds are a good example. Bolts can also offer huge holding strength. Even massive structures like trucks and commercial buildings are sometimes put together using bolts. The bolts are held in place using nuts, and the nuts can typically be tightened very snug by using a pair of pliers or even a wrench.

The wheels on your automobile, for instance, are probably bolted into place and the lug-style nuts are tightened using a tire changing tool or a pneumatic wrench that is powered by compressed air. That kind of tight fit ensures that they won’t shake loose, even under the intense force of bouncing down the road at high speeds over bone-jarring terrain. The bottom line is that when you want a prescription for great strength, holding power, or the convenience of disassembly that is relatively easy, nuts and bolts may be the ideal solution.

Other Related Tips

• Oftentimes if you are using nails to construct something, you may also consider proper adhesives to help bind the joints together. That additional support takes some of the pressure off the nails, because as you now know, nails don’t perform that great under pressure.

• When using screws in materials that don’t hold so well – like sheet rock walls that don’t have wooden studs behind them to screw into – you can buy specialty fasteners. These combine the screw design with devices such as anchors or toggles that spread open inside the wall. If the screw tries to fall out, the anchor acts kind like the nut on a bolt to hold it there. One way to think of those specialty screws is to imagine that you are trying to pull a straight piece of pipe through a hole in the wall. That might be easy. But if you try to pull a mop handle with a mop head attached through that same hole, it will be impossible because the head is too large. The anchors and toggles on specialty screws behave kind of like that mop head to keep the shaft of a screw from becoming dislodged and falling out of its hole.

• Washers are flat discs that resemble flattened-out donuts, and oftentimes using those in combination with screws or bolts can provide a stronger hold, plus give you a protective buffer so you don’t scratch up whatever it is surrounding the screw or bolt. There are even specially-shaped washers called cup washers that are a good choice for aesthetic or decorative reasons, because they are more attractive. So if you are using screws that are exposed, and a clean and neat finished look is important, you can use cup washers.

Always keep in mind that nails, screws, and bolts can fail if the material they are embedded into becomes weak enough and deteriorated enough. Also choose the right gauge and type of metal recommended by manufacturers or local building codes, to ensure that the nails, screws, and bolts you use are appropriate to the task. Safety comes first, and that’s why there are a variety of fasteners – including nails, screws, bolts, and specialty fasteners – available to today’s consumers and contractors.