Everything you wanted to know about screws . . . and didn’t think to ask

The History of Screws

Screws – the simple mechanics of a helix thread wrapped around a cylinder - so basic, yet transformative in today’s world of complex machinery and construction. From cars and skyscrapers to computers and furniture, much in our lives is fastened together by screws. The earliest screws were used in ancient Greece as presses for olive oil and wine, and later were refined to press wood pulp into paper during the Middle Ages. This simple machine allowed force beyond human strength to be applied for extracting oils, juices, paper and more.

And what if that force was applied to keeping objects fastened together?  First wood, then metal screws were handcrafted through the Middle Ages.  The dawn of the Industrial Revolution during the late 1700s generated demands for fasteners that were stronger than nails, and consistent in size. A British instrument craftsman, Jesse Ramsden, developed a lathe that cut screws to relatively uniform sizes, and American machinist, David Wilkinson, is credited for inventing machinery that ramped up the mass production of screws to meet the growing needs of various industries.

Standardization of screw sizes, heads, tips, materials, threads and more continues to evolve, even today,  as nations share manufacturing and engineering platforms that require compatibility for worldwide use.

Original screws had one slot for flat-bladed drivers. As complex machines like cars were developed, the simple screw was taken to the next level with the invention of a square drive screw (the Robertson screw) and its close cousin, the Phillips drive screw. These screws were able to handle the greater torque needed for tighter fastenings. Over the years, thousands of screw and driver varieties were developed. Screwheads, sizes, angles, threads, materials and drivers are all part of today’s construction, industrial, and technological world. Witold Rybczynski’s book “One Good Turn: A Natural History of the Screwdriver and the Screw,” published in 2000 (and available online) concludes that the simple screw changed the course of civilization.  

Screws and drivers evolved from the industries they were used for, with added features, advantages, and different materials. Screws are often named for the person or company who tweaked them (Phillips, Robertson, Torx, Pozidriv to name a few).  Then there are descriptive names for screw heads like Pan head, Cheesehead, Counter sunk, Dome head, Button head and Mirror Screw head. Add to that, the many types of screws developed for specific uses like Cap screws, Wood screws, Machine screws, Self-tapping screws, Drywall screws, Set screws and Double-ended screws.

What materials are screws made from? And why are other materials layered or added to screws?

Screws start with a steel base, which is a combination of iron and carbon, two natural elements. Other elements are added to the screw or coat the screw for strength, corrosion resistance, weight and looks. The basic screw is made from low to medium weight carbon steel wire and is relatively inexpensive to manufacture and purchase. But cheap screws can ruin quality workmanship.

Stainless steel screws with other metals like aluminum, iron, magnesium, zinc, copper and silicon added, greatly enhance the strength and durability of many screws. Depending on the combination of materials used in manufacturing screws, they may be magnetic, corrosion resistant, lightweight, shiny, colorful or even dull. For example, steel screws with added elements are stronger, copper screws provide excellent corrosion resistance, aluminum screws are lightweight and titanium screws combine strength, with corrosion resistance, and are still very lightweight. There are hundreds of in-between screw combinations, each with their own properties and advantages.

What screws to use?

Start by knowing your project. Will the screws be hidden or visible? What materials will they be holding together? Will the finished project be indoor, outdoor, or around water? And what kinds of heat, cold and weather will the project be in? This is the time to consult the pros at Leola Fasteners.

Screws are popular with most wood-based building projects because screw threads grip tightly and are less likely to loosen or pop out when the wood expands or contracts. They also reinforce the structural integrity at joint positions. Whatever your project, there is most certainly a special screw to help fasten parts together . . . and many are self-explanatory. For example, decking screws are used to fasten decks boards but the exact kind of screw depends on the type of material being used – the type of wood, composite materials, metal or wood undersides, what kind of product is it being attached to and the weather it will face. Engineered wood products, hard wood, and metal fasten more effectively after drilling pilot holes. Cement and brick require masonry screws and special drivers when fastening frames, shelves, and mantles. Wet conditions, especially near a beach, lake or river, require screws that are corrosion and water resistant – most often stainless steel with specialty coatings of zinc and aluminum.  

Self-tapping screws are another tweak of the standard screw that saves time, energy and effort. Most builders feel they are worth the extra expense as they drill and fasten in a single step. These screws help prevent wood from splitting and there is less potential damage whether you are screwing a hammock hook into a tree or joining angled beams together. It does take a certain amount of skill, though, so beginners should practice on scraps or drill small pilot holes.

Torque and pressure combined with a simple machine like a screw holds our world together – our homes, cars, computers, furniture, appliances and more. There are specialty fasteners for almost every project, made from a variety of materials. How do you know which fasteners and drivers to use? Plan your project, do your research and check in with the pros at Leola Fasteners (717) 656-0256 for top quality products and advice. Quality fasteners are an essential part of any project so that it stays sturdy, and lasts a lifetime.