Metric cable glands are the precision-engineered brass fittings used to anchor and seal electrical cable entries at the wall of an enclosure, junction box, or piece of electrical equipment. The gland performs three essential functions simultaneously: it provides mechanical strain relief on the cable (preventing pull-out forces from being transmitted to the internal connections), it seals against water and dust ingress at the enclosure wall (typically rated IP66, IP67, or IP68 depending on the design), and it grounds the cable's metal armor or screen to the enclosure body (where the cable construction includes such elements).
The gland body has metric threads on the entry side — M16, M20, M25, M32, M40, M50, M63, and so on — sized to match the standard metric knockout holes machined into European-style electrical enclosures. The other end of the gland has a clamping mechanism that compresses around the cable jacket, providing both the seal and the mechanical anchor. Inside the gland body, an EPDM or NBR sealing insert provides the primary watertight seal between the gland and the cable.
The gland family includes several variants for different cable construction types. Unarmored cable glands are the simplest — they grip and seal only the outer jacket of a basic insulated cable. Armored cable glands include a secondary clamping ring inside the body that grips the metal armor (steel wire armor or steel tape armor) of armored cables, providing both mechanical and electrical continuity to the armor. Screened cable glands include a metal ferrule that contacts the cable screen and grounds it to the gland body, then through the gland threads to the enclosure ground.
Material construction is typically C36000 free-machining brass for general industrial work, with nickel-plated brass for marine and corrosion-prone environments, and 316 stainless steel for chemical and offshore applications. ATEX/IECEx certified variants for hazardous locations are produced from the same materials but with additional construction features.