Cable connectors
Blanking plug
Blanking plugs - protection and sealing function in one
No matter whether they are threaded or lamellar, made of steel or plastic: Blanking plugs are used to close open tube ends or threaded holes and to protect them from penetrating water and dust. Depending on the design, blanking plugs are self-sealing or equipped with an additional sealing ring.
Our range includes high-quality blanking plugs from Lapp and WISKA with metric and PG threads, as well as models specifically for cable entries.
What is a blanking plug?
Blanking plugs are usually round and flat plugs that have a hexagon bolt or slot for screw fastening in a threaded hole or a pipe end using a screwdriver. Depending on the variant and material, blanking plugs for holes are self-sealing or feature a separate O-ring, e.g. made of resistant nitrile butadiene rubber (NBR). Our range of maintenance-free blanking plugs includes, among others, blanking plugs from Lapp made of nickel-plated brass, stainless steel or polyamide.
In addition to blanking plugs for screw connection, there are also versions made of plastic which are held in the bore hole by means of flexible lamellae.
Blanking plug materials and their use
Blanking plugs made of metal with metric, imperial or PG threads are temperature-resistant and are characterised by their high strength. This allows a screw connection with a high torque and a form-fit connection with the respective threaded hole to be made.
Blanking plugs made of stainless steel and nickel-plated brass are corrosion-resistant and are also used to seal heating and water pipes, among other things.
Blanking plugs made of plastic are also suitable for use at both high and low temperatures and are used, among other things, in chemical and laboratory technology because they demonstrate a high degree of resistance to oils, fuels and other organic compounds. Plastic models are available in various colours or RAL shades, including: Blanking plugs in grey (RAL 7035), blanking plugs in black and blanking plugs in white.
Thread sizes of blanking plugs in inches, metric and millimetres
Blanking plugs are available to suit the connector of various threads and are also available as reducers with an additional internal thread, including: Metric blanking plugs, NPT blanking plugs (imperial), as well as PG blanking plugs. In addition to inch versions made of metal - e.g. blanking plugs with 3/4 inch male thread - they are available in metric sizes from M12 to M63. In addition, our range from WISKA and Lapp includes plastic blanking plugs for PG threads, as well as blanking plugs with seals.
| Millimetre | Metric | Inch (NPT) | PG |
| 6 | M6 blanking plug | NPT 1/4"" | - |
| 8 | M8 blanking plug | NPT 3/8"" | - |
| 10 | M10 blanking plug | NPT 1/2"" | - |
| 12 | M12 blanking plug | NPT 3/4"" | PG7 |
| 16 | M16 blanking plug | NPT 1"" | PG11 |
| 20 | M20 blanking plug | NPT 1 1/4"" | PG 16 |
| 25 | M25 blanking plug | NPT 1 1/2"" | PG21 |
| 32 | M32 blanking plug | NPT 2"" | PG29 |
| 40 | M40 blanking plug | NPT 2 1/2"" | PG36 |
| 50 | M50 blanking plug | NPT 3"" | PG42 |
| 63 | M63 blanking plug | NPT 3 1/2"" | PG48 |
| 75 | M75 blanking plug | NPT 4"" | - |
Where are blanking plugs used?
Blanking plugs are suitable for sealing a cable gland and for other applications, including the following:
- Blanking plugs for sealing heating pipes (self-sealing blanking plugs for heating made of stainless steel or nickel-plated brass)
- Borehole blanking plugs with lamellae
- Blanking plugs for the electrical sector made of plastic
- Cable blanking plugs
- Blanking plugs for sealing tubing and other wires
What types of blanking plugs are there?
We stock blanking plugs made of plastic from the company Lapp, as well as blanking plugs made of nickel-plated brass. In addition, our range includes stainless steel blanking plugs, as well as ATEX / EX blanking plugs for use in potentially explosive atmospheres.
Overview of metric threads for cable glands
| Nominal size metric | Clamping range (approx. Information) |
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. Information) | 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 PG 13.5 | 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
But no matter whether it is a Wiska cable gland or a Lapp cable gland e.g. Skindicht or Skintop gland: The mode of operation is similar for all manufacturers. Therefore, a connector has a seal as well as a union nut and a locking nut.
Overview of the materials in connectors
| Type by material | Area of application | Advantage / disadvantage |
| Plastic cable gland | Distribution boxes, control cabinets, photovoltaics | Cheap and lightweight / not electrically conductive |
| Stainless steel cable gland | Hygienic areas, shipbuilding, ATEX / Ex-EMC | Corrosion-resistant / high weight, comparatively expensive |
| Metal cable gland | Plant, vehicle and mechanical engineering | Robust, temperature-resistant / high weight |
| Brass cable gland | Shipbuilding, ATEX / Ex-EMC | Temperature-resistant / high weight, comparatively expensive |