Despite their small and simple design, cable glands are an important component of electrical installations. They are used in nearly all areas of industry and trade.
They allow strain-relieved, water-protected cables to be connected to systems such as junction boxes, distribution boards and switchboards. Cable glands protect electrical components against mechanical and environmental forces such as dust and moisture by connecting the cables securely to casings.
Cable glands consist of three main parts: the cap nut, sealing insert and fitting. So-called EMC inserts may also be used for WISKA cable glands for electromagnetic compatibility. This eliminates the need for special EMC cable glands. Other cable gland designs include ex-cable glands, which are used in hazardous areas, and special hygienic design cable glands, which are used wherever sanitary conditions are necessary (e.g. in the food industry).
Cable glands typically have metric threads that meet global standards. However, standardised steel conduit threads (PG) can also be used. The corresponding glands are called PG cable glands. Unlike in Europe, the standardised, self-sealing NPT thread (national pipe thread) is widely used in the US market. Depending on the application, threadless cable entries may also be used instead of threaded cable glands.
Thread chart
Thread | Pitch | Major diameter | Tap drill diameter | Minor diameter |
M12 x 1.5 | 1.5 | 12.0 mm | 12.0 + 0.2 mm | 10.6 mm |
M16 x 1.5 | 1.5 | 16.0 mm | 16.0 + 0.2 mm | 14.6 mm |
M20 x 1.5 | 1.5 | 20.0 mm | 20.0 + 0.2 mm | 18.6 mm |
M25 x 1.5 | 1.5 | 25.0 mm | 25.0 + 0.2 mm | 23.6 mm |
M32 x 1.5 | 1.5 | 32.0 mm | 32.0 + 0.3 mm | 30.6 mm |
M40 x 1.5 | 1.5 | 40.0 mm | 40.0 + 0.3 mm | 38.6 mm |
M50 x 1.5 | 1.5 | 50.0 mm | 50.0 + 0.3 mm | 48.6 mm |
M63 x 1.5 | 1.5 | 63.0 mm | 63.0 + 0.3 mm | 61.6 mm |
M75 x 1.5 | 1.5 | 75.0 mm | 75.0 + 0.4 mm | 73.6 mm |
Thread chart
Thread | Pitch | Threads per inch | Major diameter | Minor diameter | Tap drill diameter |
PG7 | 1.27 | 20 | 12.5 mm | 11.28 mm | 12.5 + 0.2 mm |
PG9 | 1.41 | 18 | 15.2 mm | 13.86 mm | 15.2 + 0.2 mm |
PG11 | 1.41 | 18 | 18.6 mm | 17.26 mm | 18.6 + 0.2 mm |
PG13,5 | 1.41 | 18 | 20.4 mm | 19.06 mm | 20.4 + 0.2 mm |
PG16 | 1.41 | 18 | 22.5 mm | 21.16 mm | 22.5 + 0.2 mm |
PG21 | 1.58 | 16 | 28.3 mm | 26.78 mm | 28.3 + 0.2 mm |
PG29 | 1.58 | 16 | 37.0 mm | 35.48 mm | 37.0 + 0.3 mm |
PG36 | 1.58 | 16 | 47.0 mm | 45.48 mm | 47.0 + 0.3 mm |
PG42 | 1.58 | 16 | 54.0 mm | 52.48 mm | 54.0 + 0.3 mm |
PG48 | 1.58 | 16 | 59.3 mm | 57.78 mm | 59.3 + 0.3 mm |
Thread chart
Thread | Pitch | Major diameter | Tap drill diameter |
NPT 1/4" | 1.41 | 13.7 mm | 14.1 + 0.2 mm |
NPT 3/8" | 1.41 | 17.1 mm | 17.4 + 0.2 mm |
NPT 1/2" | 1.81 | 21.3 mm | 21.6 + 0.2 mm |
NPT 3/4" | 1.81 | 26.7 mm | 27.0 + 0.2 mm |
NPT 1" | 2.21 | 33.4 mm | 33.7 + 0.2 mm |
NPT 1 1/4" | 2.21 | 42.2 mm | 42.5 + 0.2 mm |
NPT 1 1/2" | 2.21 | 48.3 mm | 48.7 + 0.2 mm |
NPT 2" | 2.21 | 60.3 mm | 60.7 + 0.2 mm |
NPT 2 1/2" | 3.18 | 73.0 mm | 73.1 + 0.4 mm |
NPT 3" | 3.18 | 88.9 mm | 89.0 + 0.4 mm |
NPT 3 1/2" | 3.18 | 101.6 mm | 101.6 + 0.4 mm |
NPT 4" | 3.18 | 114.4 mm | 114.4 + 0.4 mm |
Despite their simple look, WISKA cable glands are components of the highest technology. They are the result of decades of development and innovative expertise. WISKA cable glands are used worldwide in various branches of industry and ensure technical systems to operate reliably.
The right cable gland for every application
The founders of WISKA developed the first plastic cable gland back in 1925, laying the groundwork for the company’s comprehensive cable gland range today. WISKA’s product portfolio comprises cable glands made from plastic, stainless steel and brass, and in many different designs, from standard to highly specific models. Among the product range are threadless cable entries and a wide array of accessories. WISKA can also make customised designs for customers with specific requirements.
1925 WISKA introduces the first plastic cable gland, made from Duroplast (ISOSTABIL), to the market.
1989 WISKA develops the modular cable gland system SPRINT.
2000 WISKA develops QUIXX®, the first dual-component cable entry in the world.
2007 The world’s first breathable cable gland with pressure equalisation, VentGLAND®, is produced by WISKA.
2010 WISKA develops an innovative membrane cable entry with strain relief (CLIXX®).
Today WISKA offers a comprehensive range of cable glands for various industries including wind and solar energy, transport engineering, shipbuilding, the offshore industry, lighting technology, mechanical and plant engineering and the chemical and food industries.
The SPRINT® cable gland system by WISKA has a modular design. Its components are completely compatible with one another and offer a solution for virtually any installation. SPRINT® cable glands are available in brass, stainless steel and plastic, and are suitable for use in a wide range of applications and branches.
The comprehensive cable gland range offers metric, PG and NPT threads in various lengths, as well as cable glands that can be used in temperatures down to as low as -60 °C. Custom designs, such as different thread types and special seals, can be made upon request.
Quick and easy installation
SPRINT® cable glands are easy to combine and require only a single, size-dependent installation tool. A 4-in-1 principle means every cable gland has a simple and precise construction: four elements – the cap nut, sealing insert, an optional EMC insert and fittings – gives a SPRINT® cable gland. Whether they’re made of plastic, brass or stainless steel, all cable glands have identical clamping ranges. The comprehensive range of multiple sealing inserts, reduction sealing inserts and special sealing inserts is compatible with all types of material and a wide variety of cable entries. The SPRINT® cable gland system fulfils all requirements for the protection classes IP 68 and IP 69.
SPRINT distinguishes itself in the efficient installation of the WISKA cable gland system. The components can be easily combined and require only a single, size-dependent installation tool
The SPRINT® cable gland range offers special solutions for unique demands such as cable glands with flex and bend protection. Spiral-shaped cable glands ensure maximum security and the protection of flexible cables, making them even safer to use.
WISKA also offers SPRINT® cable glands with integrated or additional external strain relief that prevents mechanical forces from interfering with the cable connections. The patented WISKA lamella system ensures optimal sealing and strain relief.
WISKA also offers SPRINT cable glands with integrated or external strain relief that prevents mechanical forces from interfering with the cable connections
WISKA offers two different EMC cable gland solutions for protection against electromagnetic interference. EMC cable glands are available with either an earthing cone or a contact spring insert. EMC cable glands by WISKA guarantee effective 360° shielding and long-lasting imperviousness with a protection class of IP 68/69K.
The ex-cable glands by WISKA are the perfect option for applications in hazardous areas. Explosion-proof cable glands are available with various types of ignition protection according to ATEX guidelines, IECEx standards, Inmetro requirements and EAC norms.
WISKA’s ex-portfolio encompasses everything from cable glands, screw plugs and extensions to adapters.
Electrical installations that are subject to major temperature fluctuations and high moisture require a unique solution. WISKA’s innovative pressure equalisation cable gland VentGLAND® contains a semi-permeable ePTFE membrane, which ensures constant pressure equalisation between the inside and outside of the casing.
VentGLAND® allows the casing to breathe. In this way, pressure equalisation cable glands minimise the hazard of condensation formation.
The VentPLUG is used when a cable gland with an additional pressure equalization unit is required to vent the enclosure.
Pressure equalization units from WISKA are now also available in thread sizes M 20 and M 40, in addition to M 12. Both feature a flat, space-saving design to enable flexible usage. Thanks to an improved membrane, the air flow rate of the new VentPLUG in the sizes M 20 and M 40 has more than doubled. The high air flow version even achieves a 2.5 times higher value.
You may also use our venting calculator to compute the optimal application of our pressure equalization products.
As a further unique solution, WISKA also has cable glands with hygienic designs in its range. The stainless steel cable gland HatGLAND guarantees “clean” cable entry. It is ideal for use wherever sanitary conditions are necessary such as in the food, chemical and medical technology industries.
Because of their versatile design, WISKA seals guarantee maximum stability for virtually all cables for a wide variety of applications. The comprehensive WISKA sealing insert range is continually being expanded. It encompasses reduction sealing inserts including special designs for low temperatures, blind sealing inserts, multiple sealing inserts and special sealing inserts for flat cables.
As an alternative to cable glands, WISKA also has membrane cable entries in its product portfolio. CLIXX® enables simple cable entry with soft components with strain relief. CLIXX® can be installed without a counternut or a tool: simply click and insert the cable. QUIXX®, a dual component cable entry with thread or click insertion, supplements the membrane range. It enables the insertion of multiple special cables and replaces cable glands for standard installations.
The threadless CLIXX cable entries are considerably flatter than conventional threaded cable entries