Guide to Fasteners

Reviewed by David Carmichael, Solution Engineer (March 2024)

In this guide, we delve into what fasteners are, the variety of fasteners available, and how to choose the right one for your specific needs. Whether you're in engineering, construction, or manufacturing, understanding fasteners is paramount to any project. 

Let's delve deeper into the world of fasteners and find the best solution for your task.

Fasteners are a broad range of key components used to securely join or fasten two or more objects together. They are available in a multitude of shapes, sizes, and materials, each designed to serve a unique purpose. From screws and bolts to nuts and washers, the range of fasteners is vast and largely depends on your application. 

Fasteners play a pivotal role in many industries. Their usage spans construction, manufacturing, automotive, electrical installations, machinery assembly, and even everyday applications. Fasteners maintain the integrity, stability, and longevity of structures, equipment, and products. They ensure components remain securely connected and can withstand external forces such as vibrations, tension, or shear. Without fasteners, assemblies could fail, leading to expensive repairs, safety hazards, or production delays.

How Do Magnets Work?

Magnets work based on the principles of electromagnetism. At the atomic level, magnets are made up of many atoms, with electrons orbiting the nucleus. Electrons have a property called spin, which gives them a magnetic moment, making them act like tiny magnets.

In magnetic materials, the magnetic moments of a significant number of electrons align in the same direction due to the atomic structure of the material. This alignment creates a magnetic field.

The magnetic field flows from the magnet's north pole to its south pole, creating a loop. When two magnets are brought close to each other, their magnetic fields interact. If opposite poles face each other, they attract; if the same poles face each other, they repel. This interaction is the basis of how magnets work.

What are Magnets Made of?

There are several types of magnets, made of different materials:

• Ferromagnetic Materials: These are the most common materials used for permanent magnets. They include iron, nickel, cobalt, and some alloys
• Rare Earth Magnets: These are strong permanent magnets made from alloys of rare earth elements. The most common types are neodymium magnets (NdFeB) and samarium-cobalt magnets (SmCo)
• Alnico Magnets: Made from aluminium, nickel, and cobalt, alnico magnets are known for their strong magnetic fields and high resistance to demagnetisation. They are commonly used in sensors, motors, and loudspeakers
• Ceramic or Ferrite Magnets: These are made from ceramic materials, specifically ferric oxide mixed with strontium or barium carbonate. While not as strong as neodymium magnets, ceramic magnets are inexpensive and offer good resistance to corrosion and demagnetisation
• Flexible Magnets: Made from ferrite powder and rubber polymer resin, these magnets are easy to cut and shape. They are weaker than other types of magnets but are versatile and can be used in various applications, such as magnetic signs and displays

The choice of material depends on the application, considering factors like magnetic strength, resistance to demagnetisation, and temperature stability.

Choosing the right fastener involves several factors, but selecting the appropriate fastener is crucial for ensuring your project's durability and functionality.

Here are some tips to help you select the right fastener:

• Determine the specific requirements of your project, such as load capacity, environmental conditions, and material compatibility
• Consult relevant standards and guidelines to ensure compliance with industry specifications
• Consider the aesthetics of the fastener if it will be visible in the final project
• Take into account the tools and equipment available for installation

By carefully considering these factors and following the tips mentioned, you can confidently select the right fastener for your project, ensuring its success and longevity.

Fasteners can be made of many materials. Different materials offer varying levels of strength, corrosion resistance, and suitability for specific applications. Common materials include brass, nylon, and stainless steel.

• Stainless steel fasteners are ideal for external use as they are highly resistant to rust and corrosion. A2 (304) and A4 (316) are two of the most common stainless steel grades. Both offer good resistance to corrosion and withstand high and low (cryogenic) temperatures. However, A4 grades are more corrosion resistant than A2. A4 should be chosen for higher corrosive or chemical environments, as well as marine conditions
• Brass is a copper alloy which is more expensive than steel but provides better corrosion resistance. Brass fasteners are often used in marine applications and electrical and plumbing installations due to their conductivity and water resistance. They are also used in applications where a decorative finish is required
• Nylon fasteners are lightweight and non-conductive, making them suitable for high-voltage assemblies and applications requiring increased insulation resistance. They offer good value and are ideal where a corrosion-free solution is required
• Zinc plating provides a moderate level of corrosion resistance, making it suitable for indoor use in a dry environment
• The thicker zinc coating on hot-dipped galvanised steel provides better corrosion resistance, making it suitable for outdoor applications. The finish is typically dull and rough. It's also worth bearing in mind that only galvanised washers and nuts fit galvanised fasteners
• Nickel and chrome-plated steel has a smooth, polished appearance and is used where a decorative finish is desired. Nickel plating gives moderate corrosion resistance
• Alloy steel is used when high-strength fasteners are required. It is usually produced with a black oxide finish which offers minimal resistance to corrosion and so is not recommended for outdoor use
• Titanium fasteners are non-toxic and offer lightness and very high corrosion resistance which makes them ideal for applications where these attributes are vital. However, they are more expensive than other material types

The different fastener head types include:

• Cheese: A cylindrical-shaped head with straight sides that sits above the material surface
• Button: Consists of a low-profile, rounded, dome-shaped head, typically with a slotted or hex socket drive
• Socket: A narrow head with a hex socket drive
• Countersunk (raised): Fastened into a countersunk hole and with an oval, raised head for decorative purposes
• Countersunk (flat): Fastened into a countersunk hole with the head sitting flush with the material surface
• Pan: Consists of a raised, domed head which sits above the material surface
• Hex: Used for larger bolts and set screws. Fastened with a spanner or socket

Different types of fasteners serve various purposes. Understanding these can help you choose the right fastener for your application as each type has distinct characteristics and is designed for specific applications.

At RS, we offer a wide range of fasteners to meet your needs. Whether you're looking for screws, bolts, rivets, or any other type of fastener, you can find it in our extensive selection. Browse our website to explore our range and find the right fasteners for your projects.