Fasteners Selection Guide
Introduction
Choose from our most popular range of fasteners. We have over 9,000 fasteners, fixings, ironmongery and hardware products online in a variety of materials and with RS Pro quality.
Online, you'll also find hose clips, anchors and channel supports, in a variety of materials, from leading manufacturers plus RS Pro quality.
Sections within this guide
Fastener Materials
There are many materials fasteners can be made from. Hover over the images to find out which material will suit your job.
Zinc
Hot dipped galvanised steel
Stainless steel
Brass
Chrome and nickel plated steel
Alloy Steel
Nylon
TitaniumHover
Hover over a material to find out more.
Zinc Plated Steel
Zinc plating provides moderate corrosion resistance suitable for indoor use in a dry environment.
Hot Dipped Galvanised Steel
Hot dipped galvanised steel has a thicker zinc coating for better corrosion resistance, making it suitable for outdoor use. The finish is typically dull and rough. Only galvanised nuts and washers will fit galvanised fasteners.
Stainless Steel
Stainless steel offers good corrosion resistance, making it suitable for outdoor applications, but is more expensive than zinc plated or galvanised steel.
The two most common grades of stainless steel are A2 (304) and A4 (316). Both grades will offer a good form of corrosion resistance and both are able to handle low (cryogenic) and high temperatures. A4 grade has a higher corrosion resistance than A2 grade and should be chosen in higher corrosive and chemical environments, including contact with dilute sulphuric acid and acetic acid. A4 should be chosen for marine conditions.
Brass
Brass is a copper alloy which is more expensive than steel but provides a better level of corrosion resistance. It is used when a decorative finish is required and also in marine applications.
Chrome and Nickel Plated Steel
Chrome and nickel plated steel have a smooth, polished appearance and are used where a decorative finish is desired. The nickel plating gives moderate corrosion resistance.
Alloy Steel
Alloy steel is used when a high strength fasteneris required. Usually produced with a black oxide finish which offers little corrosionresistance and so is not recommended for outdoor use.
Nylon
Nylon fasteners offer good value and are ideal where a corrosion-free, lightweight solution is required. They offer good insulation resistance and can be used in high voltage assemblies.
Titanium
Titanium fasteners are non-toxic and offer lightness and very high corrosion resistance that makes them ideal for where these attributes are vital. Comparatively more expensive than other types.
Common Fastener Types and Accessories
Hex Bolts
Hex Set Screws
Wood Screws
Self-drilling and Thread-forming Screws
Machine Screws
Socket Screws
Carriage Bolts
Nuts
Washers
Select a fastener
Click on a fastener to find out more.
Hex Bolts
Hex bolts are partially threaded and are used in machinery and construction applications. Can be used with a nut or in a tapped hole and are tightened with a wrench.
Hex BoltsHex Set Screws
Hex set screws are similar to the Hex bolt but are fully threaded instead of partially threaded. They are also used in machinery and construction applications and can be used with a nut or in a tapped hole.
Hex Set ScrewsWood Screws
Wood screws are primarily used in carpentry applications. They provide a strong clamping force which strengthens the joint between two materials. Wood screws are suitable for fixing hinges, bolts, locks and other door hardware.
Wood ScrewsSelf-drilling,
Self-tapping
and Thread-forming Screws
These are screws which form a thread as they are inserted. The choice of screw used will depend upon the material, its thickness and the application. A pilot hole may be required.
Self-drilling, self-tappingand thread-forming screws
Machine Screws
Machine screws are fully threaded and are used with a nut or in a tapped hole. They can be used in many applications where a high strength fastener is not required. The drive type dictates the appropriate screwdriver required.
Machine ScrewsSocket Screws
Socket screws have an internal hex drive and are tightened using a hex key. Often they are used in applications where there is limited clearance. A headless version is available and is known as a socket set screw or grub screw.
Socket ScrewsCarriage Bolts
Carriage bolts, also known as coach bolts, have a domed head with a square section underneath that pulls into the material or a square hole to prevent spinning during installation.
Carriage BoltsNuts
Nuts are used with machine threaded fasteners in through-hole applications. Hex nuts are the most common type and are for general-purpose fastening applications. Other types are chosen depending on the application required. These include locking nuts, which are used when a greater resistance to vibrations and torque is required.
NutsWashers
Washers are generally used with a machine threaded fastener and nut to spread the load over a greater surface area when tightening a bolt, screw or nut.
WashersHead Types
Hover over a fastener to discover more about head types.
Hex
Used for larger bolts and set screws. Fastened with a spanner or socket.
Pan
Consists of a raised, domed head which sits above the material surface.
Countersunk (flat)
Fastened into a countersunk hole with head sitting flush with the material surface.
Countersunk (raised)
Fastened into a countersunk hole and with an oval, raised head for decorative purposes.
Socket
Narrow head with a hex socket drive.
Button
Consists of a low profile, rounded, dome-shaped head, typically with a slotted or hex socket drive.
Cheese
A cylindrical shaped head with straight sides that sits above the material surface.
Drive Types
Slotted
Highly versatile, most commonly used in woodworking applications.
Pozidriv
An improved version of the traditional Phillips drive. Pozidrives are less likely to cam out and allow for greater torque pressure.
Hex Socket
Used with a Hex key in applications where there is limited space.
Torx
Very common in automotive applications and highly resistant to slippage or cam-out.
Security
A range of tamperproof types with a spigoted recess virtually eliminating unauthorised removal.
Sizing
Finding the right fastener for the job can be hard, Click to expand to find out what specifications you may require.
Measuring Diameter
The diameter is measured across the threaded portion on the outside of the thread.
Measuring Length
Countersunk fasteners are measured over the whole length. All other types are measured from under the head. Fastener length is measured from where the material surface is assumed to be, to the end of the fastener.
Measuring Thread Pitch
Metric fasteners have a specific thread pitch depending on the size and thread type of the fastener.
Generally the thread pitch is the distance between threads expressed in millimetres (measured along the length of the fastener). For example a thread pitch of 1.5 means that the distance between one thread and the next is 1.5mm.
Nut and Washer Sizes
Nut and washer sizes indicate the size of screw or bolt they fit.
In the case of metric machine threaded fasteners, the thread size will denote the size of screw or bolt required.
Grades and Strengths
The fastener grade indicates the mechanical properties of the material and is stamped onto the head of a bolt or screw.
A higher number indicates a stronger, more hardened material. So grade 12.9 will be stronger than 10.9.
A manufacturer's stamp may also be marked.
Technologies we offer
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