Choosing the correct length of a cable tie can be at times confusing, as there are dozens of different lengths to choose from, and typically manufacturers and cable tie suppliers only advise you of the "absolute maximum bundle diameter" that the cable ties are suitable for. But just because there is an absolute maximum bundle diameter for a cable tie, it doesn't make this a practical and convenient recommendation for day-to-day use.
Additionally, as you begin to tighten the cable tie, the shape of the ties resembles more of a 'teardrop' shape, rather than being a perfect round circle - and the extent of this effect also depends on the thickness of the cable ties or how stiff the cable ties are. This means that theoretical bundle diameters that are measured in perfect round shapes are even less helpful in practice.
To make things worse, the maximum bundle diameter can also vary between different types of cable ties, and there isn't a consistent answer that is helpful in practice. Therefore, we would like to present you with a simple rule to always ensure you have a cable tie that is long enough for your use, and also convenient for you to use.
The One Rule You Need to Know
So, what is the rule to find out the minimum length of a cable tie you require? It is simple: Simply take the thickness or diameter of the bundle need to tie, and multiply this by five.
By ensuring that your cable tie is at least five times the length of the diameter required, will ensure that you have long enough of a cable tie that is also practical and convenient to use.
Here are some examples:
| Diameter / Thickness | Minimum Length | Recommended Length |
| 10 mm | 50 mm | 80 mm |
| 15 mm | 75 mm | 80 mm |
| 20 mm | 100 mm | 100 mm |
| 25 mm | 125 mm | 140 mm |
| 30 mm | 150 mm | 150 - 160 mm |
| 35 mm | 175 mm | 200 mm |
| 40 mm | 200 mm | 200 mm |
| 45 mm | 225 mm | 250 mm |
| 50 mm | 250 mm | 250 mm |
| 55 mm | 275 mm | 300 mm |
| 60 mm | 300 mm | 300 mm |
Finally, to make things even easier and to ensure you always have a cable tie at hand that is the perfect length (for cable bundles up to 74 mm in diameter); you could always order one of our handy cable tie assortments that have the most popular sizes included.
A banana for scale
Below is a banana with one of our most popular 200 x 4.8 mm cable ties. Why a banana, you say? Why not, we say! It is a standardised measure for scale and size - is it not?
And as you can see; even if the theoretical maximum bundle diameter for a 200 mm cable tie is 50 mm, there isn't that much space left due to the 'teardrop' shape the tie forms naturally when being tightened. Not at least for being able to use the cable tie as conveniently as one would like.
Therefore, by remembering to use this simple rule - you'll be always sure to have a cable tie that is long enough and convenient to use!
Still need help? Get in touch and we're happy to help!
If you require further assistance in choosing the perfect cable tie for your use, please don't hesitate to get in touch by sending us an email at: sales@cableties.co.uk
Please note that we are unable to advise you on bananas.