Screws are probably the most useful and versatile fasteners for woodworking. The reason of this popularity, most likely, lies in the reliability that wood screws offer in all different applications along with their relatively low price and availability in almost all hardware store.
What is more, the market offers a vast range of products that fit perfectly all the different tasks that need to be carried out, the heaviest as well.
The choice of the right product is not always easy and entails an adequate knowledge of all diverse features.
Steel, brass, bronze, aluminium, are some of the most common materials the screws are manufactured with. Among them steel wood screw are definitely the most reliable in terms of strength and likely, the most inexpensive whereas the other ones find their proper application in particular tasks or when must have a particular appearance.
Another fundamental distinction has to be made between the multi-purpose wood screws that are widely employed in DIY projects or to join cabinet and furniture parts, and lag bolt or structural screws that are suited to secure heavy pieces of wood to each other and provide superior fixing performances in construction field and carpentry.
Lag screws (or lag bolts), are similar to wood screws but they have a larger diameter and length and a hexagonal head threads. Usually, they have to be installed with a wrench, differently by other ones that require a screwdriver. DIN 571 is the international reference standard of lag screws.
Structural screws are a relatively new type of fastener. They feature a double advantage. Thanks to their thinness and sharpness, they can be more easily assembled without any pilot hole, saving therefore, time and efforts.
Moreover, in spite of a wimpy-looking appearance they are manufactured by a hardened and high-quality steel that gives them an improved resistance and guarantee a more resilient connection between materials.
Regardless material and purpose, the wood screws can be also classified on the basis of the shape of head and type of drive. The shape of the head has a significant impact in how well the wood screw works in any particular application. Among the large variety of shapes, four are the most common and used for wood working.
Countersunk (or flat) head screws sink flush with the work surface and are commonly employed both in soft and hard woodworking applications when the screws need to concealed below the woods surface. A previous countersunk hole is usually required for better results.
Very similar are the raised (or oval) head screws featured by a countersunk and a slight domed head. They are mainly used for decorative purposes.
Hexagonal (or Hex) head screws have a flat underside and sit above the surface of the material. This shape of the head can be easily found on larger screws, because it allows a higher torque during the tightening process. As said before, this kind of head is generally applied in lag screws.
When it comes to the types of drive the choice is nearly endless. However, four are the most common types supplied by the market.
Slot screws are the traditional screws created during the 1800s and for several decades represented the best fastening solution because they are simple and cheap to produce. They have two driving points and can be driven by a common flat-blade. However, because of their shape, this kind of screws are less performant in terms of tightening.
Slotted wood screws tend to slip off the screwdriver or driver bit (cam-out process). Nowadays they are mostly applied when a Retro style is expected, such as in the restoration of old furniture.
Phillips head screws (PH), developed in the 1930s, rapidly stood out in the fastener’s market thanks to their four driving points that improved tightening performances. They are featured by a cross-slot recess that automatically centres on the tip of the screwdriver. Even though this kind of screws are still very used, they have a tendency to cam out, especially when used with power drivers.
For this reason, during the 60s an enhanced version of cruciform head screws was developed: Pozidriv screws (PZ). They look like Phillips screws but they have four additional contact points that provides a better grip between the screw head and the screwdriver and more torque to be applied.
Torx head screws (TX) are a relatively new type of screws that are becoming more and more popular among wood worker. The secret of their success lies in two features that make them easy-to-use with power drivers.
Their recess sticks perfectly the driver bit forming a temporary connection. This peculiarity allows wood workers to drive the screws without holding onto them. In addition to this, Torx screws offer a better resistance to cam-out. Structural wood screws have usually a Torx head.
Vipa spa offers a wide selection of wood screws available in many sizes, specifications and materials. A qualified support team is ready to welcome all the customers’ exigencies, leading them throughout the purchasing process.