Last updated: August 17, 2021

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If you are a professional carpenter, or if you just happen to be a fan of the DIY movement, which consists of building and assembling your own objects, you need tools to help you fix the pieces of wood you are working with. Today we'll talk about the most convenient: wood screws.

Carpenters have a wide range of fastening tools to choose from. One example is glue, although glue can sometimes be not so strong, and applying it can be messy. Screws do not have these drawbacks, as they are as easy to install as they are to remove, and their strength is unparalleled.

Although screws may seem simple enough (and they really are), there are some relevant details and points that you probably didn't know about them. That's why we've created this guide to them. Here you will learn how to distinguish the different types of wood screws and their various uses.




Summary

  • A wood screw is a small, elongated, threaded metal part whose purpose is to join pieces of wood together, or to fix objects to the surface of a wooden component. They penetrate the surface and are driven into the wood by twisting.
  • Although there is often some confusion about this, screws as such have flat ends, while those with sharp ends are called self-tapping screws. Screws require pre-drilled holes and reinforcement with nuts, whereas self-tapping screws do not.
  • Although the appearance of the different types of screws is very similar, their performance is not. In order to choose the most suitable screw for each task, it is important to consider the shape and slot of the head, the size, the tool with which it will be installed and the material of manufacture.

The Best Wood Screw: Our Picks

Wood screws are everywhere. They are so common and ubiquitous that it is sometimes difficult to know where they come from and what level of quality they are. In this ranking we list some of the most reliable and highest quality wood screw sets that allow you to build with peace of mind.

Buying Guide

Are you ready to build amazing and useful pieces with wood? Don't wait any longer! In this section we go over the characteristic factors of wood screws so you can get started as soon as possible. Here you will learn how to identify each type of screw and how to choose the one that suits you best.

The drill is a tool that facilitates the insertion of screws into wood (Photo: photosforyou / pixabay.com)

What is a wood screw and what are its advantages?

A wood screw is a small elongated piece of metal that penetrates wooden components for the purpose of joining them or fixing objects to their surface. They provide a high level of fastening, greater than other fastening methods such as glue, and removing them is almost as easy as installing them.

These tools are available in a variety of sizes, shapes and materials. Unlike nails, which are smooth and are installed with the blows of a hammer, screws have threaded bodies and are driven into the wood by the torque provided by a screwdriver or drill.

Advantages
  • High level of fastening
  • Universally available
  • Highly accessible
Disadvantages
  • Easily lost
  • Can cause injury
  • In some cases, require nuts

Standard and self-tapping screws - what should you pay attention to?

Many people believe that the screw always has a sharp point. However, this conception is somewhat erroneous. Technically, screws have a flat point, while screws with a sharp point are called lag screws. There are some slight differences between the two:

Standard screw

Its tip is flat. The protrusions or recesses of the cylinder are more compact than those of a lag screw. It is usually slightly thicker and requires a pre-drilled hole to be installed, as it is not able to penetrate the material on its own.

When passing through the wood surface, it must be secured with a nut on the other side, which increases the clamping force. For this reason, it is ideal for joining large parts with considerable weight, as well as in cases where the parts already have holes in them.

Self-tapping screw

Also known as a lag screw. It has a sharp point capable of penetrating the wood on its own, allowing the screw to advance as it is turned. Therefore, it does not require a pre-drilled hole.

They do not require a nut, and all the clamping force comes from the screw itself. They are suitable for situations where the load and fastening requirements are lower, as well as in circumstances where a drill or other drilling device is not available.

Standard screw Self tapping screw
Tip Flat Sharp
Requires pre-drilled hole Yes No
Fastens on opposite side with nut Yes No
Suitable for large and heavy workpieces Yes No

Buying Criteria: Factors that allow you to compare and rate different models of Wood Screws

Although they are small and may look very similar to each other, not all screws are the same, and the results that can be achieved with each type vary considerably. The following four buying factors help you understand what you need to consider when choosing the ideal screw.

This factor is divided into two parts. The first is the shape of the head, which relates to the fastening and finish of the final product. The second is the type of groove they have, which determines what type of tool you should use to tighten the fastener. Let's look first at the shape of the head and then at the groove:

  • Flat head: Screws with this type of head are the most recommended for carpentry. Being thin and with a uniform surface, the flat head is flush with the wood when the screw is inserted all the way in, which is convenient if the desired result is a smooth surface without protrusions.
  • Rounded head: If the piece of wood you are working with is too thin, and for this or some other reason you need to use washers, a rounded head screw is the solution. This type of head, unlike the flat head, protrudes from the surface of the material when the screw is inserted all the way in.
Slot name Slot shape Tool suitable for tightening
Single slot Single cross slot Single screwdriver
Phillips Cross Cross screwdriver
Torx Star Torx / Star screwdriver
Allen Hexagonal Allen key

Size

As a general rule, the length of the screw you choose should not be less than half the thickness of the material into which it is being inserted. In the case of standard flat-head screws only, the length should be at least two centimetres longer to allow for the installation of the nut.

The size of the bolt must also be taken into account. The greater the clamping force required (or weight, if not), the larger the bolt size must be. The size is represented by a whole number. Each size represents a diameter, which is usually measured in inches ("). Some of the most common gauges are:

Gauge Diameter (fraction) Diameter (decimal)
#3 7/64" .099"
#4 7/64" .112"
#5 1/8" .125"
#6 9/64" .139"
#7 5/32" .151"
#8 5/32" .165"

Installation Tool

The screws are inserted into the material by applying torque to them. This force can be applied manually using a screwdriver (or similar tool, such as an Allen key, depending on the type of head slot) or with the aid of a drill. Both are efficient, but vary in ease and conditions of operation.

Drill

Requires a power source. Most have power cords, although some include rechargeable batteries. Must be operated with caution, as careless use can cause serious injury. To insert a screw using a drill, a drill bit is required whose gauge is compatible with that of the screw.

The use of a drill is indispensable when working with standard flat-head (non-self-tapping) screws, unless the surface is already pitted. This is because the drill is the only tool with which the material can be drilled to allow the screw to pass through (remember that the standard screw does not have a sharp point).

Screwdriver

This consists of an elongated metal section whose tip is inserted into the slot in the head of the screw, and an ergonomic handle that allows the tool to be rotated. Although it can be used with any screw and any type of wood, it is not recommended for long screws and very rigid wood because it causes hand fatigue.

It is important that the tip of the screwdriver you choose matches the slot in the head of the screw. Otherwise, you won't be able to apply torque, or you could sweep the screw out. We recommend avoiding those with a completely rigid handle (plastic or metal, for example) because they can cause your hand to tire more quickly.

Choose the type of wood screw that suits you best (Photo: Alexas_Fotos / pixabay.com)

Material

Wood screws should always be made of metal. Plastics are not rigid or strong enough. We suggest that your first choice should always be stainless steel screws, as they are strong, durable and suitable for outdoor use. Nickel-plated and zinc-plated screws are also good choices.

Some people often opt for screws made of steel or alloys that include very strong metals such as titanium. While there is nothing to stop you working with these screws, they can be overkill when working with wood, as wood is not a very rigid material.

(Featured image photo: Alexas_Fotos / pixabay.com)

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