T5 and T8 "Tombstone" Tube Lamp Holder
T5 and T8 "tombstones" are key components used in the assembly of fluorescent and LED tube light fixtures. The term "tombstone" refers to the lamp holders that hold the fluorescent and LED tubes in place. These lamp holders are designed to secure the ends of T5 and T8 fluorescent and LED tubes, which are types of light bulbs characterized by their tubular shape and the numerical designation that indicates their diameter in eighths of an inch.
T5 tombstones are used with T5 tubes, which are 5/8 of an inch in diameter, while T8 tombstones are used with T8 tubes, which are 1 inch in diameter. These tombstones not only hold the tubes in place, but also provide the electrical connection necessary to power the bulb. They are typically made of durable plastic and metal components to ensure a safe and secure connection.
For functionality, a fluorescent or LED tube must be inserted into a tombstone at each end of the fixture and then rotated to lock in place, thereby completing the circuit. Each "tombstone" tube holder has two wires. In standard configurations, one tombstone's wires are both live, and the other's are both neutral. However, alternative configurations may include one live and one neutral wire on one end, with the other end remaining inactive.