Replacing a lampholder on an old table lamp, repairing a chandelier or making a new light fitting? The mounting thread is often the first thing you need to identify.
A thread-mounted lampholder screws onto a matching threaded support, usually a hollow tube through which the cable passes. Choosing the correct replacement means checking the mounting thread, lamp cap, shade fixing and any switching requirements.
1. Check the mounting thread
The first question is how the lampholder attaches to the fitting.
10mm threaded entries are common on table lamps and many other fittings. We also stock selected lampholders with larger and less common threaded entries, including ½-inch and 20mm options.
The important thing is to match the actual thread. Similar-looking fittings are not necessarily interchangeable, particularly when working with older or imported lighting. Both the thread diameter and thread form need to be compatible.
If you're unsure, measure the existing mounting arrangement and check the product specifications before ordering.
2. Choose the right lamp cap
The mounting thread and the lamp cap are two separate things.
Common lamp cap types include:
BC / B22: Standard bayonet cap
ES / E27: Large Edison screw cap
SES / E14: Small Edison screw cap
SBC / B15: Small bayonet cap
Other cap types are available within our wider lampholder range, but not every combination of lamp cap and mounting thread is offered.
When replacing an existing lampholder, check both the bulb fitting and the mounting arrangement rather than assuming one determines the other.
3. Will the lampholder support a shade?
Some thread-mounted lampholders have a smooth outer skirt, while others have a threaded skirt designed to accept shade rings.
These are different from the mounting thread at the back of the lampholder.
For a shade-fitting arrangement, check the shade opening, lampholder body, appropriate shade rings and how the shade will be supported.
As a general guide, many conventional BC shade fittings use an opening around 29–30mm, while ES/E27 fittings commonly use approximately 40mm. These are not universal dimensions, so check the individual product and shade before ordering.
Shade rings are not included with every lampholder. The product page should confirm what is supplied.
4. Do you need a switch?
Thread-mounted lampholders are available in switched and unswitched versions.
Depending on the design, switched versions may use a push-bar, rocker or pull-chain mechanism.
An unswitched lampholder may be more appropriate where the light already has a suitable inline, base-mounted or separate switch.
Consider how the finished light will be used. For delicate or decorative fittings, a separate switch can sometimes be more convenient than operating a switch directly on the lampholder.
5. What if the threads don't match?
An otherwise suitable lampholder may have a different thread from the existing support.
Thread reducers and increasers can sometimes solve this problem by adapting one thread size to another.
We stock a selection of threaded adaptors for common lighting applications. The adaptor must match both connections correctly and provide a suitable mechanical fixing.
Don't force a near-fitting thread or assume that matching the nominal diameter is sufficient.
6. Metal or plastic lampholders?
Both metal and plastic lampholders have their uses, depending on the design of the complete fitting.
Metal lampholders are available in a range of finishes and can be particularly useful when restoring traditional lighting. Plastic versions are often practical where their construction and appearance suit the application.
Electrical safety must be considered across the complete light fitting, not just the lampholder. A metal lampholder with an earth terminal does not automatically establish correct earthing throughout the fitting, and using a plastic lampholder does not automatically make an assembly double-insulated.
The mounting, electrical connections, insulation, protective earthing where required, and final testing must be suitable for the complete assembly. Electrical installation and testing should be carried out by a competent person.
Need help finding the right lampholder?
Unusual threads and older lighting parts can be difficult to identify, especially when the original component is no longer made.
If you're unsure what you need, send us a photograph of the existing lampholder, the mounting arrangement and any relevant measurements. We can help identify a suitable replacement or practical alternative.
Browse Thread-Mount Lampholders
Ask Lampfix for help identifying a part