A Guide to Buying Grommets
Let’s start with whether you want an open grommet (one with a hole through the middle), or a blind grommet to blank off a hole?
We’ll start with Open Grommets – there are three critical dimensions (A, B & C), and two normally non critical ones. These dimensions are shown below :
- Dimension A – the panel hole, or the hole the grommet fits into
- Dimension B – the thickness of the material the panel hole has been made in
- Dimension C – the size of the hole through the grommet
In most instances dimension C will be the least important of the three as the function of the grommet is normally cable protection. The D dimension (overall thickness of the grommet) and E (outside diameter) are non-critical and are proportional to the overall size of the grommet.
Always be aware of the dimensional difference between the A and C dimensions. The greater the difference the firmer the grommet will be and the more difficult it will be to install. For example, what you don’t want to be trying to find is a 25mm A dimension with a 5mm C dimension as this will be a solid mass!
Next we have the colour, the standard being black but we do hold stock of some white grommets in both the open and blind categories.
All PVC grommets can be produced in a range of colours. A RAL number would be required, and it would be subject to a minimum batch quantity as defined by production. This would apply to both open and blind grommets.
The next item is material, and again this applies to both open and blind grommets. Most of the items we manufacture are made from a flexible PVC compound, which is ideal for most applications with a temperature range of -35c to +70c. We also manufacture items in TPR (thermoplastic rubber) and this has a temperature range of -30c to +130c.
Blind Grommets are used for blanking off a hole. Semi-Blind Grommets are used in applications when a hole needs to be blanked off but with the option to pass a cable or item through at some later stage. Blind grommets only have two critical dimensions – the panel hole (A), and the panel thickness (B).
IP Sealing Grommets are designed to create a water and dust tight seal rated to the standard of IP 66/67. To achieve this standard of fit the grommets must be used to the dimensional criteria as specified on this website. These items are manufactured in TPR for a greater range of temperatures.
We have eleven different types of Assorted Blanking Grommets that are available to be viewed online and are available for immediate shipment. As the name suggests these parts are used to blank off a hole.
Sleeved Grommets are designed to provide support to the cable when used in applications where cable movement is expected on the sleeve side of the grommet.
Quick Fit Grommets are an alternative to standard open grommets, and these are effectively a push fit application, ideal when the cable is in a static situation.
Push Fit Blanking Plugs are for use in blanking holes that are no longer required for access. These parts can accommodate variable panel thicknesses.
Snap Fit Blanking Plugs are ideal in applications when access is required. The grommet can easily be removed and is easy to install.