Fluorescent tubes generally have a two-pin fitting at both ends of the tube and generally, length goes hand in hand with wattage – the longer the tube the higher the wattage.
T12 38mm (G13) Fluorescent Tubes
The largest size T12 (38mm) is no longer being manufactured, however, they did use the same G13 cap as the T8 fluorescent tube which means that you can replace the T12 tubes with the more efficient T8 of the same length. See T8 section below for suitable alternatives.
T8 26mm (G13) Fluorescent Tubes
Standard size T8 (26mm) tubes use the G13 fitting with 13mm between the two pins.
T5 15mm (G5) Fluorescent Tubes
The small T5 (16mm) tubes use the G5 fitting with 5mm between the two pins.
T4 12mm (G5) Fluorescent Tubes
The undercabinet T4 (12mm) tubes use the G5 fitting with 5mm between the two pins.
T2 7mm (W4.3) Fluorescent Tubes
The ultra-slim T2 (7mm) tubes use a fitting called a W4.3 with 4.3mm wide push-fit fitting.
Colour Temperature
Although most lamps emit white light, this can vary from a cosy warm white to a cold white according to the colour temperature of the lamp. The following chart shows the code numbers used for some of the most popular types:-
| Colour Temp | Colour Code | Designation | Application |
|---|---|---|---|
| 2700K | 827 | Very warm white | Similar light to incandescent light bulbs, giving a warm cosy feel |
| 3000K | 830 | Warm white | The colour of most halogen lamps. Appears slightly whiter than ordinary incandescent lamps |
| 3500K | 835 | White | The standard colour for many fluorescent and compact fluorescent tubes |
| 4000K | 840 | Cool white | Gives a more clinical or high tech feel |
| 6000K | 860 | Daylight | Fluorescent or compact fluorescent lamps simulating natural daylight. |
| 6500 | 865 | Cool daylight | Extremely white light used in specialist daylight lamps |
Colour Temperature Codes (for illustration only, colours may not be exact)
You can read our guide to find out more about colour temperature.
Colour Rendering Definition
The Colour Rendering Index is an industry-standard reference to a light bulb on how well it renders colours of objects it is illuminating. Codes range from 0 to 100, the higher the number the more vivid and lively things look under that light. The lower the CRi rating the more ghostly (faded, dead) objects appear.
If you want your items and people to look good, then high CRi is required. High CRi light bulbs generally cost more to buy and cost more to operate as they have low lumen output per watt consumed. Low CRi light bulbs put out low-quality light, but are very cheap to operate as they have high lumen output per watt consumed.
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Need T2,15w,6400k bulb for bathroom cabinet
Hi, I’m looking for 1500mm by 26mm tube. The box from the old tube says 5200 Lumen and 68 KWh F58W/835
Which tube can I order from your site?
I have an older big electronic bug killer that takes F25ft8/350BL bulbs that cost $35 a piece and are eighteen inches long. F15t8 bulbs are also 18 inches long and 8 to 10 bucks. Will this cheaper bulb work in its place?
Although it will fit and work, the UV light output will be less, so it may not be as effective in attracting those bugs.
I have two different types of 4-foot tubes and I want to make sure I order the same but the letters and numbers do not match – I have L36W/23 and I have F40W/W-RS. Can you please advise what I need to order as replacements? Thank you – Peter
From my research, the L36W/23 is a T8 tube, and the F40W/W-RS is a T12 tube – to confirm, can you see if the tubes are the same thickness? The T12 should have a wider diameter. Then, is there any indication on the fitting which type of tube should be used T8 or T12, or an indicated wattage 36W or 40W? T8 tubes are far, far more wide spread in use than T12 tubes, so I would suspect you require a 36W 4ft T8 tube of which you can choose from a selection of light colours, Warm White, White, Cool White or Daylight.
Hi can you help me please, looking to replace the following fluorescent tube bulbs, WL2001-6W ,8W and 24W T5 220-240V 50HZ G5,with possibly LED tube lights? What do you recommend? Thank you.
Hi, our experience with these slimmer tubes (T5 and ultraslim) is that LED tubes are not particularly compatible with the transformers in the relevant light fittings. Many manufacturer’s of LED T5 tubes require that the fittings are even re-wired to bypass the transformers, which is a complete headache. For this reason, we do not stock LED T5 tubes. Our advice would be to stick with fluorescent, or swap out the fittings entirely for integrated LED fittings.
I have an Osram LUMILUX HO54W/840 which I want to replace. It is 116 cm long and has a diameter. Of 15 mm. Do you have it? jon_phillips@mail.com.
Hi Jon, you can replace with this Crompton Lamps Fluorescent 1149mm T5 Tube 54W HO High Output Cool White.
Hi guys … I am planning to make an exposure ‘light box’ for screen printing. I would like to use 5, Sylvania UV tubes (BL368). Friends now tell me that I may need ballasts … ? What do you say and how would it (they?) be wired to the lamps? Please advise … Cheers – Steve
Hi Steve, yes, UV tubes use the same technology as fluorescent tubes, so need to be controlled by a ballast and starter to work. The easiest way would be to purchase 5x fluorescent T8 battens in the length you require, then you can simply mount the battens to your light box and insert the tubes into them. We do not sell said battens, but a quick search on google and you will find many DIY stores that sell them for £12-18 each for a 5ft length.
I have fitted a new tube and started motor but the light is still flickering on and off. Any idea how I can fix this?
To deduce, if its a new tube and a new starter, then the only other variable is the ballast in the fitting, which must be failing.
Is there an equivalent for the T2 640mm 15W 6400k
Thanks,
Richard
Hi Richard, nothing that we sell – but you may find other sellers with this item by searching Google
Hi Richard, I need same bulb for bathroom cabinet, did you manage to get one ?
F18W/35 – what is the bulb on your website that will match this fluorescent tube?
Hi Elizabeth, this Crompton Lamps Fluorescent 2ft T8 Tube 18W Triphosphor White F18W/835 should be the same.
I have been looking for a replacement florescent tubes for our undercounter kitchen lighting. I have been searching at Home Depot, Ace, Lighting stores and on line for 3 months now and I cannot find the replacement tubes that I need. The replacement tubes need to be F10T5/cool white 10 watt. this tube is total length (including connecting prongs) is 50mm or 16 3/8 inches, Diameter is 5/8 inches. Can you tell me if these are still available and where I can find them. Thank you
David Blakeslee
Hi David, that is an unusual size and we don’t offer anything that matches. Searching around the internet it looks like the tube you are after is a Philips branded tube, part number 046677417277, but I’m not seeing many sellers of this item, I feel it has probably been discontinued. You may be best advised to upgrade your kitchen lighting and we do offer a range of under cabinet kitchen lights, if you choose that option.
Help please I need to replace a crompton 13w 835 A01 fluorescent tube tight measuring 65cm or 23 inches without pins. Thank you.
Not quite sure, as your measurements are not the same, but this is the only Crompton 13W fluorescent tube 835 we stock
How do i replace an old starter for a 48inch tube?
I’d really like to send an email to someone to ask for advice but I can’t locate an email address. Basically I need to order 2 x F16W 135 T8 warm white. What product code?
Hi Chris, please visit out Contact Page. Alternatively – is Sylvania Fluorescent 29″ T8 Tube 16W Warm White what you are looking for?
Im Trying to build a moveable wall of 8 ft x 6 ft with a florescent tube 1 ft apart the whole way down the wall is this possible with just the tube showing not the whole tin housing
For a fluorescent tube – inside the tin housing is a transformer and starter gear, which could get hot so would not be advisable to hide inside a wall. Also fluorescent tubes must be connected at both ends. Have you considered an LED tube? They can be connected to one side only and can be powered straight from mains without the need of a transformer or starter.
Dose the fluorescent tube size include the pins
If you check the specifications on our product pages such as this Fluorescent T8 5ft 36W tube, you will see we state the length with and without pins. But generally, there is no variance between lengths. i.e. a 5ft tube fits all 5ft fittings, you won’t find a 5 1/2 foot or a 4.8 foot for example. You can also match by the wattage, for example all T8 tubes that are 36W are also 5ft – this is because the length of the tube is directly proportionate to the wattage. So if your old tube was 36W, just buy a new 36W tube (or a 36W equivalent LED alternative).
Why don’t they put the color of the light on the tube. ? So I know what color to buy again.
Sometimes the colour is written in different ways. Look out for 3000K, 4000K, 6000K or 6500K which denotes the colour temperature in Kelvins. These can sometimes be written as 830, 840, 860 or 865 – where the 8 denotes that a triphosphor coating is used with a colour rendering index of 80+ and the next two digits are the first two digits of the colour temperature. Lastly, what is the colour of the light to look at; is it yellowish (3000K/830), white (4000K/840) or bluish (6500K/865).
Thanks for clearing up a query that was giving me a headache. Was trying to find a 4ft tube with a 38mm diameter which is apparently the old style tube and hard to find as discontinued. You can now use the newer T8 tube which is 26mm diameter but with the same end fittings. Many thanks.