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 TempColour CodeDesignationApplication
2700K827Very warm whiteSimilar light to incandescent light bulbs, giving a warm cosy feel
3000K830Warm whiteThe colour of most halogen lamps. Appears slightly whiter than ordinary incandescent lamps
3500K835WhiteThe standard colour for many fluorescent and compact fluorescent tubes
4000K840Cool whiteGives a more clinical or high tech feel
6000K860DaylightFluorescent or compact fluorescent lamps simulating natural daylight.
6500865Cool daylightExtremely 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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Steve

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.

Ken

How do i replace an old starter for a 48inch tube?

Teres

Why don’t they put the color of the light on the tube. ? So I know what color to buy again.

Ralph

Dose the fluorescent tube size include the pins

Richard Latham

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 

Chris B.

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?

Sue

Help please I need to replace a crompton 13w 835 A01 fluorescent tube tight measuring 65cm or 23 inches without pins. Thank you.

David Blakeslee

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

Elizabeth

F18W/35 – what is the bulb on your website that will match this fluorescent tube?

RICHARD

Is there an equivalent for the T2 640mm 15W 6400k
Thanks,
Richard