Wire end ferrules and in particular the colour coding of wire end ferrules are indispensable in electrical installations. They protect the strands of electrical cables from damage, create a secure connection to different types of cable terminals and ensure that there are clear assignments. The colours of the wire end ferrules facilitate the selection and installation of the ferrules. The ferrule colour code provides clear information during installation as to whether the ferrule matches the cross-section of the cable used. In addition to the answer to the frequently asked question: What are wire end ferrules?, this guide also contains a wire end ferrule colour code table.
What are wire ferrules?
Wire end ferrules, also known as cable sleeves or ferrules in English-speaking countries, are small metal tubes that are usually made of tinned copper. They are available in different sizes and diameters for cables with different cross-sections. The most widely used ferrules are now available in colours in accordance with DIN 46228. In addition to the frequently asked question: "What are ferrules?", their function is usually also questioned and why the same size ferrule is available in different colours. The wire end ferrule, which is available in several cross-sections depending on the standard, is indispensable for protecting individual stranded cables. Wire end ferrules help to prevent the strands from fraying, breaking or disintegrating. In addition, wire end ferrules ensure easy connection to the cable terminals and a secure electrical connection between the cable and the terminal. To fit the wire end ferrules, they are simply pushed over the stripped wires or strands and then crimped tight using suitable pliers. It is also important to note that, depending on the application, there are insulated or uninsulated wire end ferrules. The insulated versions, e.g. wire end ferrules in DIN colours, have a plastic collar for this purpose, while an uninsulated version consists only of the conductive metal tube.
The colour coding of the wire end ferrules indicates for which cable cross-sections the respective wire end ferrule is permissible. As wire end ferrules are also frequently used in industry, especially when cables are connected to terminals, the colour coding of the wire end ferrule is an important aid. This ensures that the cross-section of the cable used matches the ferrules or is permissible according to the colour code and is neither too small nor too large. In Germany, ferrules in different colours according to DIN 46228 are generally used. We have summarised which colours are used in this article in a colour code table for wire end ferrules.
Meaning of the colours of ferrules
There are various standards, e.g. DIN 46628, which specify the cross-section of the wire end ferrule using different colours. The ferrule colour code according to DIN 46228 thus clearly indicates the maximum cross-section of the cable with which a ferrule can be crimped according to its colour. The wire end ferrule according to DIN 46228 is available in a total of 6 colours. However, the colours of the ferrules according to DIN only provide limited information about the size, as there are different sizes that have the same colour. It is therefore important that the manufacturer's specifications are always observed when using DIN 46228 wire end ferrules so that the colour coding of the wire end ferrules corresponds to the installation specifications, for example. For example, there is a risk of confusion with the colours of wire end ferrules with a cross-section of 2.5 mm. According to the German standard and the increasingly important DIN 46228, the cross-section of wire end ferrules with the colour code blue is 2.5 mm.
Common cross-section sizes einer Aderendhülse und Farben nach DIN 46228/ DIN 46628:
Colour code of the ferrules:
- Cross-section: 0.25 mm² : Yellow
- Cross-section: 0.34 mm² : Turquoise
- Cross-section: 0.50 mm² : White
- Cross-section: 0.75 mm² : Grey
In addition to the DIN wire-end ferrules colours listed here as examples, other variants are also common. The ferrules colour code table also includes the DIN-compliant colours red, black and blue.
Important for ferrules according to DIN 46228: These ferrules are available in 6 colours. Please note that the colour code for ferrules in accordance with DIN 46228 does not provide a separate colour for each available size.
Overview: Ferrule colours according to DIN, German and French standards
As already mentioned, several types of cable end sleeves are available. In addition to different sizes and cross-sections, wire end ferrules are available in different designs, e.g. as a twin version for two cables. The plastic collar insulates the cable end, but there are also uninsulated versions that do not have a collar.
Wire end ferrules with standard cross-sections and collars from 0.14 mm² to 25 mm² and larger are available on the market.
The colours of the plastic collar of a standardised wire end ferrule usually indicate the size of the cross-section. Depending on the standard, the colours of the ferrules differ even though they have the same cross-section. If in doubt, the ferrule colour code table of the respective manufacturer provides information on the size of the ferrule according to the available colours. There are also ferrules with colours according to the French standard. Their sizes are similar to those of DIN 46228, but the colours of these ferrules differ from the DIN standard. Furthermore, the wire end ferrules with DIN colours also differ from wire end ferrules with the German colour code.
The ferrule with colours according to the French colour code is available in the following common sizes, for example:
- Colour: purple, cross-section: 0.25 mm²
- Colour: Pink, cross-section: 0.34 mm²
- Colour: White, cross-section: 0.50 mm²
- Colour: Blue, cross-section: 0.75 mm²
The wire end ferrule with colours according to the German colour code is available in the following common sizes, for example:
- Colour: yellow, cross-section: 0.25 mm²
- Colour: turquoise, cross-section: 0.34 mm²
- Colour: White, cross-section: 0.50 mm²
- Colour: Grey, cross-section: 0.75 mm²
The following table with the colour coding of wire end ferrules provides an overview of the standards for wire end ferrules and their colours.
| Cross-section of the ferrule | Wire end ferrules with French colour code (A) | Wire end ferrules with German colour code (B) | Wire end ferrules with colour code according to DIN standard 46228-4 | Wire end ferrules with colour code according to DIN standard 46628 |
|---|---|---|---|---|
| 0,14 mm² | brown | grey | - | grey |
| 0,25 mm² | violett | light blue | - | yellow |
| 0,34 mm² | pink | turquoise | - | turquoise |
| 0,50 mm² | white | orange | white | - |
| 0,75 mm² | blue | white | grey | - |
| 1,00 mm² | red | yellow | red | - |
| 1,50 mm² | black | red | black | - |
| 2,50 mm² | grey | blue | blue | - |
| 4,00 mm² | orange | grey | grey | - |
| 6,00 mm² | green | black | yellow | - |
| 10,00 mm² | brown | ivory | red | - |
| 16,00 mm² | ivory | green | blue | - |
| 25,00 mm² | black | brown | yellow | - |
| 35,00 mm² | red | beige | red | - |
| 50,00 mm² | blue | olive | blue | - |
| 70,00 mm² | - | - | - | yellow |
| 95,00 mm² | - | - | - | red |
| 120,00 mm² | - | - | - | blue |
Note: A ferrule with the colours for cross-sections of 0.14-0.34 mm² and 70-120 mm² is not part of the DIN standard. However, these variants are used in practice to avoid a mixture of colour codes.
Advantages of colour coding for electrical installations
Thanks to the colour coding of wire end ferrules, it is possible to see at a glance which cross-section the wire end ferrule has, as the colours can be quickly identified visually without having to measure whether the cable fits the ferrule. Whether ferrules with colours according to DIN or the German standard, they are available in different sizes to match the respective diameter (American Wire Gauge) of the cable. In principle, the electrician is free to choose the colour of the wire end ferrules. However, control cabinets can also specify the colour code of the wire end ferrules so that the installations meet a company's standards, for example.
The importance of ferrules
As already mentioned, wire-end ferrules with colours according to DIN or another standard fulfil several important functions in electrical installations. They make an important contribution to operational safety in both industrial and private applications and make electrical installations in switch cabinets and on devices much easier. The most important functions at a glance: - Wire end ferrules protect the sensitive individual strands of a cable from mechanical stress and therefore from damage. A wire end ferrule in accordance with DIN 46228 ensures that the stranded wire neither loosens nor breaks and effectively prevents faulty electrical connections and short circuits. - Wire end ferrules improve the electrical connection: If standardised wire end ferrules with a colour code are used, the electrical connection between the cable and the connection, e.g. a screw terminal, is also optimised. The crimped wire end ferrule distributes the pressure evenly over the individual strands. At the same time, this enables a tension-resistant connection that is reliable even under difficult conditions.
Why are wire end ferrules important in electrical systems?
A wire end ferrule and its colours are an important component of electrical connections, especially when screw terminals are used. Ferrules are available in different colours according to DIN and, for example, the German standard. They are important in both industrial and private applications for a number of reasons. They give a stranded cable properties comparable to those of a solid conductor. In addition to the simple differentiation by the colours of the wire end ferrules, they offer a further advantage. For example, time-consuming and, depending on the application, risky tinning of the cable ends is no longer necessary. Another advantage of colour-coded wire end ferrules is that they enable an airtight and corrosion-resistant connection to the terminal. This means that wire end ferrules with colours in accordance with DIN or German standards significantly increase safety during operation.
Advantages of ferrules
- Quick and easy installation: All you need to install a wire end ferrule is a suitable crimping tool. Even though the colour coding of wire end ferrules makes installation easier, variants without coloured plastic collars are also easy to install. In both cases, connection to a cable is possible in just a few steps. The ferrule is pushed over the sufficiently stripped end of the cable or stranded wires and crimped using crimping pliers compatible with wire end ferrules. The entire process therefore requires only a small amount of material and is also completed quickly.
- Simple bundling of the strands: The plastic collar, which can come in different colours depending on the size of the ferrule, makes it easier to insert the individual strands into the ferrule. This ensures that each individual wire is inserted and short circuits are avoided.
- Protection against live parts and mechanical stress. The collar of wire end ferrules, with colours according to DIN or another standard, creates a barrier between the sheathed conductor and the contact when correctly installed. The collar also acts as protection against kinking and ensures that the cable sheath does not get caught in the screw terminal.
- Always choose the right ferrule thanks to the different colours: The colour coding of wire end ferrules makes installation much easier. If standardised wire end ferrules with a colour code are used during installation, there is always no doubt that the cable cross-section fits exactly into the wire end ferrule. The colour coding of wire end ferrules thus ensures considerable time savings and safety during electrical installations.
Product recommendations
Cable colours
Cable / power cable colours - What do the different colours of power cables or cables in general mean?
Cable jacket
Cable sheathing & cable insulation - properties and differences of the cable sheath at a glance
Cable designation
Cable designation illuminated: This makes it easy to identify cables
AWG in mm²
Conversion of AWG cable cross-sections to mm² - Strand construction and AWG tables
Cable protection
Cable protection - 11 ways to protect cables and wires efficiently