3M Cold Shrink Tubes Silicone Rubber – Seal, Repair, Joint, & Splice Cables

3M Cold Shrink Tubes - Silicone Rubber

3M Cold Shrink Tubes – Silicone Rubber

3M Cold Shrink Tubes

Resists Fire

Thorne & Derrick distribute Silicone 3M Cold Shrink Tubes (Fire Resistant) for sealing, repairing, jointing and splicing cables – we provide competitive prices for 3M cold shrink tubes from extensive stocks to UK and international destinations.

3M Electrical manufacture Cold Shrink from silicone material resistant to environmental stress including UV radiation, heat, moisture, oil and ozone – the inorganic silicone material resists dirt and humidity providing excellent insulation properties.

For electrical insulation of low voltage cables the cold shrink tubes manufactured by 3M Electrical create a waterproof insulating seal for most common types of rubber or plastic (EPR XLPE) insulated cables up to 1000V please see EPDM rubber cold shrink.

3M Cold Shrink tubes are simple to install as no tools are required as installation can be done by hand and once sealed the tube retains its resiliency and pressure even after prolonged years of ageing and exposure.

The fire resistant 3M Cold Shrink tubes manufactured from high stretch silicone rubber resist fire and will not support flames with an operating temperature range of -66°F/ -55°C to 500°F/ 260°C.

3M Silicone Cold Shrink

3M Silicone Cold Shrink

Silicone Cold Shrink

Silicone cold shrink tubes are open ended, silicone rubber, tubular sleeves installed onto cables, pipes and umbilicals to provide a watertight seal with additional resistance for fire, acids, ultra violet light, moisture and flame – the cold shrink tube is inherently low smoke zero halogen (LSOH). 

No special tools are required to install silicone cold shrink – the tubes are simply unwound manually to shrink down the cold shrink sleeve to form a tight seal for cable, cable lugs and cable repair or joint applications.

Flammability Testing Of Silicone Cold Shrink Products

The test for flammability of the 3M Cold Shrink Insulators 8440 Series was conducted with specimens positioned both vertically and horizontally per specification BSS 7230. The silicone rubber insulation passed the Flammability Test of BSS 7230 without supporting a flame. In addition, these 3M Cold Shrink insulators were also subjected to a gas flame test as outlined in paragraph 4.4.15 of MIL-C-24643A and met the passing criteria as specified. No fuse was blown during the one hour flame exposure.

Cold Shrink Heat Aging

3M Electrical Cold Shrink tubes manufactured from silicone rubber have been subjected to an eight hour heat aging test at 500ºF/260ºC – other cold shrink tubes were subjected to 401°F/205°C for 30 days and the silicone rubber remained resilient and showed no sign of deterioration.

Cold Shrink 3M - EPDM Rubber & Silicone Tubing For Electrical Insulation

Cold Shrink 3M – EPDM Rubber & Silicone Tubing For Electrical Insulation

Cold Shrink v Heat Shrink

Watch the following comparison video to learn about the benefits of 3M Cold Shrink technology – the cold applied Cold Shrink tubes feature an integral and intelligent live memory action or living seal that exerts a strong and constant inward force on the cable.

Cold Shrink provides excellent electrical insulation performance and environmental sealing for cables with fewer installation steps minimising the risk for installer error and reducing the installation time.

Cold Shrink Applications

Silicone Rubber Sleeves

  • Primary electrical insulation for polymeric type cables (XLPE EPR) and cable joints distributing electrical power up to 1000V
  • Suitable for electrical insulation applications in both indoor, outdoor and overhead applications
  • Physical protection and sealing against moisture for medium/high voltage air insulated cable connectors and cable lugs
  • Insulation of secondary cables splices and protection of subsea cables and offshore flexible umbilicals or cables
  • Cable sheath and cable jacket repairs

Typical Physical & Electrical Properties of 3M Cold Shrink 

Please note the following information provided by 3M Electrical Markets Division is not intended for specification purposes – values are typical, not to be considered minimum or maximum. Properties measured at room temperature 73°F (23°C) unless otherwise stated.

Physical Properties (Test Method)Typical Value US Units (Metric)
Colour Grey
100% Modulus (ASTM D 412-75) Original180 psi (1.24 MPa)
300% Modulus (ASTM D 412-75) Original450 psi (3.10 MPa)
Ultimate Tensile (ASTM D 412-75) Original1240 psi (8.55 MPa)
Die B Tear (ASTM D 642B-73) Original185 psi (1.28 MPa)


Electrical Properties (Test Method)Typical Value US Units (Metric)
Dielectric Strength (ASTM D149-75) Original @ 1.78mm 554 v/mil (21.8 Mv/m)
Dielectric Strength 168hrs in H2O @ 90°C 543 v/mil (21.4 Mv/m)


ATEX – Potentially Explosive Atmospheres & Hazardous Area Locations (HAZLOC)Cold Shrink | ATEX Explosive Atmospheres & Hazardous Area Zone Locations

Cold Shrink is subject to a Statement of Exclusion with respect to the ATEX Directive as the tubes and technology is effectively “non-sparking” when installed in accordance with 3M Electrical installation instructions and do not pose a potential explosion risk – no “hot-working” is required.

Used extensively in Zone 1 & Zone 2 hazardous areas designated according to ATEX within the EU in both onshore and offshore locations. For specification guidance about the use of Cold Shrink products, in relation to NEC, CEC, IEC & UL Classes & Divisions please contact Thorne & Derrick.

Watch Installation Video: Silicone 3M Cold Shrink Tubes

➡ Should you require customer service or technical support please contact us

3M Cold Shrink Tubes – 3M 8440 Series

The following table enables the selection of 3M Cold Shrink Tubes – three diameter sizes of 3M tubes cover a range of cables up to 1000 volts for copper and aluminium conductors

3M Silicone Cold Shrink TubeCable Range (sqmm)OD Min mmOD Max mmLength mm (A)(B) ID
3M 8443-210-356.8614.2229.2 – 39.617.3Silicone
3M 8443-6.510-356.8614.22119 – 14017.3Silicone
3M 8445-2.535-508.8918.2930.5 – 4821.3Silicone
3M 8445-7.535-508.8918.29132 – 15221.3Silicone
3M 8447-3.250-7012.1924.1348.3 – 6427.2Silicone
3M 8447-850-7012.1924.13147 – 17527.2Silicone
Silicone Cold Shrink Manufactured By 3M

Silicone Cold Shrink Manufactured By 3M

Watch 3M Cold Shrink Tube Installation Video

3M Cold Shrink Tubes Silicone Rubber

Installation Technique

1. Slide Cold Shrink insulator onto cable.
2. Install connector.
3. Remove defects from surface of cable in seal areas.
4. Hold Cold Shrink assembly and cable in proper position in one hand.
5. Unwind core in counter-clockwise direction with the other hand. Installed unit weight can be found in the table below.

Approximate Installed Weight
Terminal Lug Cold Shrink Insulators Inline Connector Cold Shrink Insulators
Part NoWeight (gm)Part No.Weight (gm)


➡ Should you require customer service or technical support please contact us – view the full range of Silicone 3M Cold Shrink Tubes below.

For LV Low Voltage Cables | Cold Shrink Cable Terminations MV | Cold Shrink Cable Abandonment | Cold Shrink Tubes

3M Cold Shrink

3M Cold Shrink

Cold Shrink Terminations 3M

Thorne & Derrick International | MV HV Joints, Terminations & Cable Connectors