4:1 Heat Shrink Tubing – Adhesive Glue Lined, Waterproof, 4–40mm

Measure the outer diameter of the cable or component you need to cover, then select a tubing size whose unshrunk diameter is at least 1.2–1.5× that measurement. For example, a 3mm cable typically fits well inside Φ4mm tubing. The 4:1 shrink ratio gives you flexibility across a wide range of bundle sizes — if you're bundling multiple wires, measure the bundle OD after grouping.

For inch-based reference: Φ4mm ≈ 5/32", Φ6mm ≈ 1/4", Φ8mm ≈ 5/16", Φ12mm ≈ 1/2", Φ16mm ≈ 5/8", Φ20mm ≈ 3/4", Φ24mm ≈ 15/16", Φ32mm ≈ 1-1/4", Φ40mm ≈ 1-9/16".

A 4:1 shrink ratio means the tubing shrinks to approximately one-quarter of its original diameter when heat is applied. This is generally double the coverage of standard 2:1 tubing, making it well-suited for irregular shapes, connectors, and bundled cables where a tighter, more conforming fit is needed.

Yes. The inner adhesive glue layer melts and flows during shrinking to create a moisture-resistant seal around the substrate. This makes it suitable for outdoor wiring, marine environments, and applications where moisture ingress is a concern. For fully submerged or high-pressure water exposure, please confirm suitability with your specific application requirements before use.

This tubing typically requires a heat source of around 120–150°C (248–302°F) to begin shrinking, with full adhesive activation generally occurring at higher temperatures. A heat gun is recommended for even, controlled shrinking. Avoid open flames, as they can cause uneven shrinkage, scorching, or damage to the adhesive layer.

Yes, dual-wall adhesive-lined heat shrink tubing is commonly used in automotive wiring harness repairs, connector sealing, and battery terminal protection. The waterproof seal and flexible recovered wall generally hold up well to engine bay vibration and temperature cycling. It is also widely used for trailer wiring, RV electrical systems, and marine wiring.

Recovered wall thickness varies by diameter. Smaller sizes (Φ4–Φ8mm) typically result in a thinner recovered wall, while larger sizes (Φ20–Φ40mm) produce a thicker recovered wall with more adhesive fill. See variant options or contact us to confirm exact recovered wall thickness for your specific size if this is critical to your application.

Available in Black, Transparent (Clear), Red, and White. Color is generally a cosmetic and organizational choice and does not affect the electrical or mechanical performance of the tubing. Transparent tubing is useful when you need to visually inspect the connection or label after installation. Red is commonly used for positive leads in DC wiring systems.

For individual repairs, a 1M or 5M length is generally sufficient for most DIY jobs. For production wiring, automotive builds, or bulk projects, 50M–200M rolls offer a lower cost per meter. The 200M roll option is available for Φ4mm sizes; larger diameters are available in rolls up to 25M–50M. Check the variant selector for available lengths per diameter.