Cable connectors
All you need to know about twist nipples
Twist nipples are accessories for electrical wiring and are, for example, used for jet-water-protected cable glands. In the sections below, you will find out all about the properties and areas of application of twist nipples.
What are twist nipples?
Twist nipples, also known as sealing plugs, are accessories for cable glands. They are used to seal cables and wires in electrical equipment. The plastic nipple is an initially closed body whose membrane is only breached with the cable entry. The seal that is than attached to the cable provides protection from external influences such as moisture, dust and other foreign bodies.
In our product range, you will find metric twist nipples from the manufacturers Lapp and WISKA. Depending on the manufacturing method, they are watertight, UV-resistant and withstand high temperature fluctuations.
Where is a twist nipple used?
Twist nipples are used in electrical engineering and permanent installations. They are used where threaded holes or simple cable ducts are sealed and no strain relief is necessary. Common areas of application for twist nipples are cable entries in mechanical or plant engineering and in electrical control cabinets.
What properties do twist nipples have?
Cable entries made of elastomer are very robust and durable and suitable for temperature ranges from -20°C to 80°C. The watertight twist nipples are IP-54 certified and are therefore ready for use in wet areas or moisture-prone rooms.
Blanking plugs made of polystyrene also have UV-resistant properties and are an inexpensive variant in the installation of control cabinets, distribution boxes and junction boxes. In comparison with plastic twist nipples, metal cable glands provide strain relief in the wire, are corrosion-resistant and have a higher IP protection class of IP68. Here, a rubber or elastomer sealing ring provides the watertight seal. Cable glands made of polyamide or polycarbonate have similar properties and are designed for high strain relief. They are also UV- and ozone-resistant. The thread sizes of metal and plastic cable glands are available with both metric and PG threads.
Overview of metric threads for cable glands
| Nominal size metric | Clamping range (approx. ) | Outer Ø of thread in mm | Pitch |
| Cable gland M12 | 3 - 7 mm | 12.0 | 1.5 |
| Cable gland M16 | 4.5 - 10 mm | 16.0 | 1.5 |
| Cable gland M20 | 7 - 13 mm | 20.0 | 1.5 |
| Cable gland M25 | 9 - 17 mm | 25.0 | 1.5 |
| Cable gland M32 | 11 - 21 mm | 32.0 | 1.5 |
| Cable gland M40 | 19 - 28 mm | 40.0 | 1.5 |
| Cable gland M50 | 27 - 35 mm | 50.0 | 1.5 |
| Cable gland M63 | 34 - 45 mm | 63.0 | 1.5 |
M Thread according to EN 60423 or IEC 423 or BS 6053 ISO 68/DIN13
Overview of PG threads for cable glands
| Nominal size PG | Clamping range (approx. ) | Outer Ø of thread in mm | Pitch |
| Cable glandPG7 | 2 - 6.5 mm | 12.5 | 1.27 |
| Cable gland PG9 | 4 - 8 mm | 15.2 | 1.41 |
| Cable gland PG11 | 4 - 10 mm | 18.6 | 1.41 |
| Cable gland PG13.5 | 5 - 12 mm | 20.4 | 1.41 |
| Cable gland PG16 | 8 - 14 mm | 22.5 | 1.41 |
| Cable gland PG21 | 11 - 18 mm | 28.3 | 1.588 |
| Cable gland PG29 | 16 - 25 mm | 37.0 | 1.588 |
| Cable gland PG36 | 19 - 32 mm | 47.0 | 1.588 |
| Cable gland PG42 | 28 - 38 mm | 54.0 | 1.588 |
| Cable gland PG48 | 34 - 44 mm | 59.3 | 1.588 |
PG Thread according to DIN 40430
In which colours are sealing plugs available?
Sealing plugs in the conventional metric thread sizes (e.g.: M 20) are available in the following colours:
- Black
- White
- Light grey (RAL 7035)
What sizes are available for sealing plugs?
Hexagonal style sealing plugs are available in the following metric thread sizes:
| Size | Diameter | Thread length | Throughput | Width across flats | Protection type |
| sealing plugs M12 | 17.0 mm | 8.0 mm | 4.0 mm - 6.0 mm | SW12 | IP54 |
| sealing plugs M16 | 20.0 mm | 9.0 mm | 5.0 mm - 10.0 mm | SW15 | IP54 |
| sealing plugs M20 | 24.0 mm | 12.0 mm | 5.0 mm - 10.0 mm | SW19 | IP54 |
| sealing plugs M25 | 28.0 mm | 12.0 mm | 9.0 mm - 16.0 mm | SW24 | IP54 |
| sealing plugs M32 | 37. 0 mm | 14.0 mm | 11.0 mm - 22.0 mm | SW30 | IP54 |
| sealing plugs M40 | 45.0 mm | 16.0 mm | 17.0 mm - 24.0 mm | SW37 | IP54 |
| sealing plugs M40 | 55.5 mm | 18.0 mm | 22.0 mm - 35.0 mm | SW46 | IP54 |
| sealing plugs M63 | 68.5 mm | 20.0 mm | 24.0 mm - 43.0 mm | SW56 | IP54 |
sealing plugs are produced not only with metric ISO threads but also with armoured threads (PG). The manufacturer WISKA delivers these in the following sizes, which you can find in our online shop:
- PG 9
- PG 11
- PG 13.5
- PG 16
- PG 21
- PG 29
- PG 36
But regardless of whether it is a WISKA cable gland or a Lapp cable gland e.g. a SKINDICHT or SKINTOP cable gland : the functioning is similar for all manufacturers and the corresponding twist nipples are available.