Screws are one of the 6 simple machines. They make our lives easier by holding 2 different materials together with tremendous strength. You likely have a drawer or box in your kitchen or maybe a closet that has a bunch of odd screws rolling around at the bottom. You might even have an old jar full of random screws that
You likely have a drawer or box in your kitchen or maybe a closet that has a bunch of odd screws rolling around at the bottom. You might even have an old jar full of random screws that has been in your family for generations. So, in this assortment, which is the one is the right choice for the project at hand?
There are numerous types of screws available today, and they can be sorted and classified many ways. Most often, screws are sorted by diameter, head type, driver type, thread, material and finish (just to name a few). Diameter is measured by using a number system, the smaller the number, the smaller the diameter. Commonly ranging from #2 through #14.
Head types include flat, pan, oval or round and washer head. The most popular drivers include Slotted, Phillips, Square or Robertson and Star drive or Torx. Also, there are many different material and finish options to choose from, some may be specific to indoor to outdoor use.
From top to bottom: Flat head, Trim head, Washer head, Pan head, Oval head, Round head, Flat head in brass, Bugle head.
Screw designs have changed over the years and are continuously evolving. You may find yourself frustrated if you are trying to drive a Slotted screw with a modern screw gun. It’s a very old design and a driver will slide right out of the slot. Save yourself some frustration and reserve this type of screw for when you are able to tighten with a flat blade screwdriver. More modern designs use very sharp, self-drilling tips and drivers like Square or Torx that grip extremely well.
Usually when we are using screws we are fastening one material to another and want a mechanical fastener with extra holding power. Nails or staples may be faster but can work loose in time. You can choose to make a screw head flush in the material and cover it or leave it proud to accentuate the design, but nearly every situation where you would use a screw is application specific.
Fig. 3 Popular Kreg pocket hole techniques utilize Washer head screws with a self-drilling tip for fast, strong joints.
Consider what materials are being put together. If it is a soft material like wood, use a flat head screw so that it sinks just flush (Fig. 4).
If it is a hard surface like metal you probably want to choose a pan head screw for better-holding power (Fig. 5).
It’s important not to over tighten screws when your materials pull tight. If you do, you run the risk of stripping the threads, which will weaken the integrity of the hold. If you need to increase holding power or disperse the pressure, use a washer head screw. Smaller head trim screws can be used if you are trying to discreetly hold down a loose board.
The next time your project could benefit from the holding power of this simple machine, try to keep in mind that each screw has been designed for a specific purpose. Put some thought into which one is best suited for your project, because in the long run you’ll save yourself some time and frustration by choosing the right screw type the first time around.
Brian Altiere of This Is Woodworking compiled this guide to choosing the right screw for your next woodworking project!