Restoring a vintage chandelier or designing a bespoke lighting fixture is a lavish pursuit that brings immense character to a home. However, as many of our customers discover, the devil is truly in the detail: specifically, the measurements. At Candle Tubes UK, we specialise in creating made-to-order candle sleeves that provide that perfect “wow” factor, but because our products are fully bespoke, we cannot accept returns.

Getting your measurements right the first time is not just prudent; it is essential. It’s not as complicated as it looks, but there are a few “nasty pinches” you’ll want to avoid. In this guide, we’ll peruse the most common mistakes and explain how our specialized digital measurement service can take the weight off your shoulders.

Are You Measuring the Old Sleeve? (The Most Common Mistake)

It seems logical, doesn’t it? If you need a replacement, you simply measure the old one. However, this is perhaps the most frequent pitfall we encounter.

Old candle tubes: especially those made of card or early plastics: often warp, stretch, or discolour over decades of heat exposure. If the original part was poorly fitted to begin with, you are simply “copying the mistake.” (Industry secret: many mass-produced fixtures originally used “near-enough” sizes rather than a bespoke fit).

The Golden Rule: Always measure the hardware, not the cover. You should measure the outside diameter of the actual electrical socket or the “candle cup” (the metal or glass dish the sleeve sits in). This ensures your new sleeve slides on smoothly without wobbling like a loose tooth.

The Inside Diameter Dilemma: ID vs. OD

When you browse our range of bespoke candle tubes, you will notice we talk a lot about Inside Diameter (ID).

• Internal Diameter (ID): This is the width of the hole inside the tube.
• Outside Diameter (OD): This is the total width of the tube including the material thickness.

A common error is providing the Outside Diameter of your old sleeve. If you order a metal sleeve with an ID of 28mm because your old one had an OD of 28mm, you’ll find the new one won’t fit over the socket! The material of the tube itself (whether it’s card, plastic, or metal) has a thickness that must be accounted for.

How do you calculate OD from ID when wall thickness varies by material?

This is a crucial technical detail, and it catches people out more often than you might think. The wall thickness sits on both sides of the tube, so you must allow for both sides when working out the Outside Diameter (OD) from the Internal Diameter (ID).

So the reckoner is:

• OD = ID + (wall thickness × 2)

For many materials with a 1mm wall thickness, the calculation is:

• OD = ID + 2mm
• Why? Because you add 1mm for one side and 1mm for the other side

For example:

• If the Internal Diameter (ID) is 28mm, the Outside Diameter (OD) will be 30mm
• If the Outside Diameter (OD) is 30mm, the Internal Diameter (ID) will be 28mm

You can think of it like this:

• ID + 1mm wall + 1mm wall = OD
• 28mm + 1mm + 1mm = 30mm

For our card candle tubes, however, the wall thickness is 1.5mm.

That means the calculation is different:

• OD = ID + 3mm
• Why? Because you add 1.5mm for one side and 1.5mm for the other side

For example:

• If the Internal Diameter (ID) is 28mm, the Outside Diameter (OD) for a card tube will be 31mm
• If the Outside Diameter (OD) is 31mm, the Internal Diameter (ID) for a card tube will be 28mm

In simple terms:

• ID + 1.5mm wall + 1.5mm wall = OD
• 28mm + 1.5mm + 1.5mm = 31mm

This distinction is particularly important when you are choosing card materials compared to other materials. If you assume every tube uses a 1mm wall and order based on that, a card sleeve may not fit as expected. For a perfect fit, always be clear whether you are measuring the hole inside the sleeve or the full width across the outside, and remember that card tubes require an extra 3mm added to the ID when calculating OD.

Top Tip: If your socket measures exactly 28mm, you’ll want a sleeve with an ID slightly larger: perhaps 29mm: to allow for a comfortable fit.

Finding the Correct Height: Where Does It Sit?

Measuring height is where most DIY enthusiasts get a bit “muddled.” You aren’t just measuring the tube; you’re measuring the gap it needs to fill.

You must identify exactly where the base of the sleeve will rest. Does it sit on a metal lip? Does it disappear into a deep candle cup?

• Rule of Thumb: Measure from the base (where it sits) up to the top of the socket insulator.
• Safety First: The sleeve should usually finish flush with the top of the socket. If it’s too tall and creeps up toward the bulb’s “shoulder,” the heat from the bulb can scorch plastic or even melt beeswax covers. (Lucky you if you’ve switched to LEDs: they run much cooler and are far kinder to your restoration parts).

Choosing the Right Material for the Job

Your measurements may be perfect, but have you considered the “reckoner” of material choice? Each material has its own quirks:

• Card & Paper: Often used for that classic “dripped” look. They are traditional but can be susceptible to damp if stored in a garage during a renovation.
• Plastic & Nylon: Our English Regency Nylon range is brilliant for modern durability while maintaining a period aesthetic.
• Metal (Brass, Copper, Steel): These provide a crisp, clean finish but remember: metal conducts heat. Ensure there is adequate clearance between the socket and the sleeve.
• Glass: Beautiful for high-end restorations, but requires a very steady hand during measurement as there is zero “give” in the material.

The Foolproof Solution: Our Digital Measurement Service

If all this talk of millimetres and internal diameters feels a bit daunting, don’t worry: it’s quite alright. We offer a specialized Digital Measurement Service designed specifically for those complex or high-value restoration projects.

Instead of reaching for the tape measure and hoping for the best, you can simply send an original part or a sample of your hardware to our workshop in Northamptonshire.

1. Contact Us: Reach out to our team at sales@candletubes.co.uk.
2. Post Your Part: Send us the original sleeve or the socket component.
3. Precision Measurement: We use digital callipers and specialist tools to find the exact bespoke dimensions required.
4. Perfect Production: We manufacture your new sleeves to these precise specifications, ensuring a “hand-in-glove” fit.

This service is particularly favoured by interior designers and professional restorers who are working on large-scale projects where “near-enough” simply won’t do.

Final Thoughts

Measuring for candle covers is a task that rewards the patient. Take your time, remove the bulb (and turn off the power!), and measure the hardware rather than the old sleeve.

Whether you are looking for a simple plastic replacement or a lavish set of hand-waxed card tubes for a historic chandelier, we are here to help. If you’re ever in doubt, just remember: it’s always better to ask us for a bit of “insider knowledge” before you hit the order button.

Our Global Reach

We proudly cater to customers across the UK, Europe, and internationally, supplying bespoke candle tubes, candle sleeves, and candle covers for restoration and new-build lighting projects alike.

You can peruse our regional websites here:

• UK: www.candletubes.co.uk
• International: www.candletubes.com
• Europe: www.candletubes.eu

So whether you are ordering from Britain, sourcing parts for a European restoration, or managing a project further afield, we are set up to help you find the right bespoke solution.

Happy restoring!