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Guide To Tube Inserts

Welcome to the Vital Parts guide to Tube Inserts!

This is your number one source of information regarding measurements, uses, variations, and sizing, all found on one page. This guide should help to educate you on some of the most common uses for these components. This includes when to use them and how to measure them, ensuring you make the best decision every time.

Tube Inserts, Tube Fittings, and Tube End Caps are a hugely popular product inside many industries. They regularly feature as a finishing component inside consumer products, from office appliances to school furniture.
Tube Inserts Guide Installation Image


  1. When to use Tube Inserts
  2. Why use Inserts
  3. Measuring up for installation
  4. How to install
  5. What's available for Tube Inserts

When to use Tube Inserts:

To finish off a tube or pipe:

A widely popular use for these Inserts is for finishing off a tube, pipe, or post. These products offer a sleek and discrete finish. As a simple to fit option, these are a go to part for most finish uses, requiring just a tap for a reliable and secure installation.

For use as feet with tubular chairs or furniture:

Another hugely popular use for these products is for use as chair or furniture feet, fitting as inserts into the end of a chair or furniture leg. Such a use offers many benefits for old or worn furniture, including added grip and reduced damage to floors. This kind of use is most frequently seen with school chairs, which have a tubular design for internal fitting of these inserts.

To protect the internal section:

Protecting the internal section of a tube, pipe, or post is an often overlooked benefit that these inserts can provide. They are able to seal an internal section from ingress. It's for this reason that Tube Inserts are an extremely popular for use with outdoor posts and metal tubing to prolong the life of an application.

To add a function:

Adding a function to a tube is a common use for our inserts. We offer many different variations available specifically for this. Adding a function to a tube is frequently done through the installation of a threaded insert or tube connector. This can allow for the attachment of externally threaded components or joining two tubes.

Why use these Inserts?

There are many different reasons as to why you may choose to use Tube Inserts over other solutions available, from ease of use to the quality of finish they provide. Below, we have listed some of the main reasons to use them.

Easy to fit:

In comparison to most other solutions, these are an extremely easy to fit product. Simply line them up with the tube before tapping into position. Each insert comes with flexible ribs to provide a secure fitting, and to prevent the need for additional fixings/adhesives.

Cost effective:

As a whole, these inserts are a relatively cost effective part that are bulk manufactured for availability in a huge number of sizes. These are a very popular choice for use over potentially expensive solutions, such as Rubber Stoppers.

Huge range of shapes and sizes:

Due to the huge amount of uses that Tube Inserts are employed for, we tend to keep a massive number of shapes and sizes in stock. This is to enable us to provide you with the best possible match.

How to measure Tube Inserts:

When looking to measure Tube Inserts, it is essential to have a good idea of the exact measurements that are required for a secure fit and a reliable finish/function. Below, we have split up some of the key measurements that need to be taken.

Please refer to the images for a visual representation.

Outside Diameter (OD)
Finding the Outside Diameter of a tube is done by measuring the distance between the two outer lips of your application. The distance between the two lips will be your measurement for the Outside Diameter.
 Outside Diameter inserts guide image

Internal Diameter (ID)
The next step to finding your measurement is to find the Internal Diameter of your tube. This is done in a similar way to the Outside Diameter, however the measurement is taken from the distance between the two inner lips rather than the outer.
 Internal diameter inserts support image

Wall Thickness (WT)
Once have the two main measurements of your tube (ID & OD) you can start to work out the Wall Thickness range that you will require for a secure fitting. This measurement is found by using the following measurement: 
(OD - ID ÷ 2 = Wall Thickness)

Wall Thickness inserts support guide

Once you have all three of the required measurements, you can start to look for your required sizing. To do this you want to match up your tubes OD with the inserts OD listed on our product page, as this will help you to identify the best fit.

It is important to make sure that the measurement that you came up with for the Wall Thickness fits inside the range disclosed on the relevant product page. For example, if you have an insert with an OD of 30mm and a wall thickness of 1-3mm, then this will fit a tube that has an OD of 30mm and a wall thickness between 1-3mm.

Please note that, in some cases, Tube Inserts are able to fit across a range of tube diameters. This is thanks to their flexible ribs, which can flex when pushed inside.

How to install Tube Inserts:

Installation, as displayed below, is a quick and simple process. Our inserts require just a tap by hand or hammer to provide a tight and secure fitting. Due to the ribbed nature of this product, these hold inside the tube without the need for fixings, fasteners or adhesives.

Fitting your insert

Installing your Tube Inserts

What’s available for Tube Inserts?

Our range of Tube Inserts feature both standard and bespoke products for a number of uses. These vary from finishing off a tube to connecting two tubes together. To get a better understanding, and to give an overview of what we have on offer, please see the different types summarised below.

Standard Inserts:

Standard Inserts are one of the most cost effective fitting options that we provide. They come in all common shapes and sizes (such as Round, Square, Rectangular). Manufactured from durable Plastic & Nylon, these are to go-to product range for most generic types of use.Standard Tube Inserts Overview Image


Threaded & Spring Inserts:

Threaded & Spring type inserts are unique in the sense that they allow for the attachment of male threaded components to a tube. They are available in a range of female metric thread sizes between M6 & M20 and a selection of shapes to suit differing tube styles.Spring Threaded Inserts image example

Tube Connectors:

Tube Connectors are a bespoke style of insert. They are manufactured specifically for the connection of tubular frames. Popular for use inside industries that deal with temporary stands and attractions, these offer the ability to connect a full metal frame.

For our full range of Tube Inserts, Threaded Inserts & Spring Inserts please click here.

For any custom enquiries, problems or questions related to these inserts then please feel free to contact us or give us a call on 01233 713581