3.2mm Dual Wall Heat Shrink Tubing 3:1 Ratio Adhesive Lined Waterproof

Measure the total run of wire or cable you need to protect, then add 10–15% for trimming and overlap. For example, a 1m (≈39.4") length typically covers small repairs or a handful of connections, while 5m (≈196.9") or 10m (≈393.7") rolls suit larger wiring harnesses or batch projects. Choose the next size up if you're unsure.

This tubing uses a 3:1 shrink ratio, meaning it shrinks to roughly one-third of its original inner diameter when heat is applied. That gives it a tighter, more conforming fit over irregular shapes, connectors, and splices compared to standard 2:1 tubing — especially useful for uneven or stepped surfaces.

Yes. Dual wall adhesive-lined heat shrink tubing is generally rated for demanding environments including automotive, marine, and outdoor electrical applications. The hot-melt adhesive inner layer bonds to the wire jacket and creates a moisture-resistant seal. For specific voltage or temperature ratings, please contact us to confirm compatibility with your application.

Yes. The adhesive inner wall melts and flows around the substrate during shrinking, creating a waterproof seal that resists moisture ingress. This makes it suitable for outdoor wiring, underground splice protection, and marine electrical connections. For prolonged submersion, contact us to confirm suitability.

The 3.2mm (1/8") inner diameter typically accommodates wires and cables up to approximately 3mm OD before shrinking. After full shrinkage at 3:1 ratio, the recovered inner diameter is generally around 1mm. Always measure your wire or connector OD and compare to the tubing's expanded ID before ordering.

Dual wall polyolefin heat shrink tubing typically begins shrinking at around 70–90°C (158–194°F) and fully activates the adhesive liner at approximately 120–150°C (248–302°F). A heat gun is the recommended tool. Avoid open flames, which can scorch the tubing unevenly.

Color choice is typically for identification and organization purposes. Black is the most common for general wiring. Red and blue are often used for positive/negative polarity coding. Transparent allows you to see the underlying wire or label. Green, yellow, and white are commonly used for ground, signal, or neutral wires respectively — though conventions vary by industry.