Heat Shrink Tubing 3:1 Adhesive Lined — 2.4mm to 85mm, Multiple Colors

Measure the outer diameter of the wire, connector, or object you need to cover. Choose a supplied diameter that is larger than your substrate — the tubing will shrink to approximately 1/3 of its supplied size. For example, a φ6.4mm (1/4") tube recovers to roughly 2.1mm. When covering a connector with a larger body, size to the connector, not the wire. When in doubt, size up one step to ensure the tube slides on easily before shrinking.

A 3:1 ratio means the tubing shrinks to approximately one-third of its original supplied inner diameter when heat is applied. This is significantly more than standard 2:1 tubing, making it ideal for stepped connectors, irregular shapes, and applications where you need the tube to slide over a large connector body and then shrink tightly onto a smaller wire. It also means each size covers a wider range of substrate diameters.

Yes. The inner adhesive layer melts during shrinking and flows around the substrate, creating a moisture-resistant seal. This makes it suitable for outdoor wiring, marine cable splices, trailer connector sealing, and generally underground cable joints. For fully submerged or high-pressure water exposure, we recommend confirming suitability with your specific installation requirements.

This adhesive-lined tubing typically begins shrinking at around 120°C (248°F), with full shrink and adhesive activation generally occurring at 135°C (275°F) or above. A heat gun is strongly recommended — it provides even, controlled heat distribution. Avoid open flames (lighters, torches applied directly), which can scorch or blister the outer wall before the adhesive has time to fully activate and flow.

Yes — these are among the most common use cases for adhesive-lined 3:1 heat shrink tubing. The dual-wall construction provides both electrical insulation and a waterproof, corrosion-resistant seal. It is widely used for automotive wiring harness repairs, battery terminal protection, trailer wiring connectors, and marine cable splicing where vibration and moisture are ongoing concerns.

Dual-wall adhesive-lined tubing generally provides superior mechanical protection compared to standard single-wall heat shrink. The cross-linked polyolefin outer wall resists abrasion, chemicals, and UV exposure. The adhesive inner layer adds strain relief at the termination point. For specific dielectric strength or voltage rating requirements, contact us to confirm the specification for the size you need.

The 1m length is ideal for single repairs or small projects where you need just enough material. The 2m length typically offers a lower per-meter cost and is the better choice for larger wiring projects, multiple connections, or if you want to keep spare material on hand. Both lengths are supplied as continuous pieces that you cut to your required length.