T5 T8 T10 T12 Diameter and length

Understanding Fluorescent Tube Diameters: The T‑Number System

When choosing or replacing fluorescent tubes, one of the most important specifications is the tube diameter, indicated by a "T" number (such as T5, T8, T12).

This standard system lets buyers quickly identify the physical size and compatibility of the tube.The letter "T" stands for "tubular", and the number that follows represents the tube's diameter in 1/8 of an inch.

Knowing the diameter of a fluorescent tube is the first step to making sure you select the right one for your fixture and lighting needs.

Green lighting has entered the homes of ordinary people, but for ordinary consumers, this thing is really incomprehensible. Let's talk about the price, ranging from tens of yuan to three or four hundred; warranty, there are one year, two years, four There are also five-year-olds; what about performance? I really don't know what to ask. So how can we find a good-looking, energy-saving, and durable LED fluorescent lamp? Let's take a look at it, let's talk about the appearance first.

1. From the diameter of the LED tube:

Mainly T5, T8, T10, and rare T12:

The word "T" comes from the English "Tube", which mainly means the tube. The number on the T side refers to the diameter of the LED fluorescent tube, in English units, and 1 T means one-eighth of an inch.

One inch is equal to 25.4 millimeters. Then each "T" is 25.4÷8=3.175mm

The diameter of the T12 tube is (12/8)×25.4=38.1 mm

The diameter of the T10 tube is (10/8)×25.4=31.8mm

The diameter of the T8 tube is (8/8)×25.4=25.4mm [The T8 tube is exactly one inch in diameter]

The tube diameter of T5 is (5/8)*25.4=15.9mm

Among traditional fluorescent lamps, T8 tubes are now the largest mainstream, T5 fluorescent tubes are mainly three-primary fluorescent lamps, and T10 fluorescent tubes are basically scarce in the market.

Since in the early stage of the development of LED fluorescent tubes, many constant current power supplies could not be miniaturized, so it was impossible to build LED constant current power supplies in T8-LED lights, so there were T10 fluorescent lights on the market, and some fluorescent tube factories were connected. T10 couldn't do it, so there was T12. However, the T10 and T12 interface cannot be used on the G13 lamp holder of the T8 lamp holder, so the above T12 and T10 lamp holders are two sections. That is, use a T10 to T8 lamp holder.

Therefore, in terms of the tube diameter of the LED fluorescent lamp, it is best to find a factory capable of developing a true T8 (within 26mm diameter). Because T8's LED fluorescent tube has been developed for more than two years now, it is still a manufacturer that is still standing in place, and its enterprising spirit can be imagined.

LED fluorescent tube purchase guide

2. From the length of the traditional lamp:

The length and power of commonly used T8 fluorescent lamps:

The length of traditional 20w fluorescent tube is 620mm, conventionally it is 2 feet, or 60cm. The power of LED fluorescent tube of this length is generally 7~10W;

The traditional 30w fluorescent tube is 926mm long, conventionally it is 3 feet, or 90cm. The power of the LED fluorescent tube of this length is generally 11~14W;

The traditional 40w fluorescent tube is 1230mm long, and conventionally it is 4 feet, or 120cm. The power of the LED fluorescent tube of this length is generally 15~20W;

Length and power of commonly used T5 fluorescent lamps:

8w length 310mm; 14w length 570mm; conventionally it is 2 feet, or 60cm, the power of LED fluorescent tube of this length is generally 5~10W;

21w length 870.5mm; conventionally it is 3 feet, or 90cm, the power of LED fluorescent tube of this length is generally 8~14W;

28w length 1170.5mm; conventionally it is 4 feet, or 120cm, the power of LED fluorescent tube of this length is generally 13~18W;

35w (length 1475mm) is usually 5 feet, or 150cm, the power of this length of LED fluorescent tube is generally 18~22W;

Matching Tube Diameter and Socket Type

Understanding the diameter of your fluorescent tube is critical, because it determines the type of socket you need.

Most standard fluorescent tubes (T8, T10, T12) use a G13 bi-pin socket with 13 mm pin spacing.However, T10 and T12 tubes are larger in diameter, so they generally won't fit directly into fixtures made for thinner T8 tubes unless you use an adapter (as mentioned in your article).

T5 tubes use the smaller G5 socket (with 5 mm pin spacing), so they are not interchangeable with T8 or T12 fixtures.

Always check both the diameter (T‑number) and the pin configuration to ensure compatibility.

When purchasing LED fluorescent tubes, try to choose a length that is common to the market, so as not to cause inconvenience in installation, and problems such as independent mold opening of the supporting parts, which increases the cost of the product.

It is best not to find some unreasonable power, for example: find a 60cm long, 20W. Except for some unscrupulous manufacturers, such LED lamps dare to do this. The regular LED fluorescent tube manufacturers will not do this, because an LED lamp is not only a question of whether it can be made, but also heat dissipation and light decay after production. , Failure rate and other factors.

Benwei T8&T5&T12 Led Tube Electronic compatibility/Directly connected to mains power

Knowledge

T5 T8 T10 T12 Diameter and length

Understanding Fluorescent Tube Diameters: The T‑Number System

Matching Tube Diameter and Socket Type