3:1 Heat Shrink Tubing with Adhesive Glue Lining — φ1.6mm to φ65mm, 8 Colors

Measure the outer diameter of the wire, connector, or object you need to cover. Choose a heat shrink tube whose expanded (pre-shrink) inner diameter is slightly larger than that measurement. For example, if your wire bundle is 3mm (≈1/8") across, a φ4mm tube generally works well. After shrinking at a 3:1 ratio, the recovered diameter will be approximately one-third of the original expanded size. When in doubt, size up — you can always apply more heat to tighten the fit.

This dual-wall adhesive-lined tubing typically requires a heat source of around 120–150°C (248–302°F) to begin shrinking, with full adhesive activation generally occurring at approximately 150°C (302°F). A heat gun is the recommended tool. Avoid open flames, which can scorch the tubing unevenly and may not activate the adhesive layer uniformly.

Yes. The inner adhesive layer melts and flows around the substrate as heat is applied, creating a moisture-resistant seal that is generally suitable for outdoor, marine, and automotive environments. For fully submerged or high-pressure water exposure, confirm the specific application requirements before use.

A 3:1 shrink ratio means the tubing can shrink to one-third of its original expanded diameter when heat is applied. This is significantly more than standard 2:1 tubing, making it suitable for irregular shapes, connectors, and stepped transitions where a tighter, more conforming fit is needed. It also means you can use a single tube size to cover a wider range of wire gauges.

Yes. Adhesive-lined 3:1 heat shrink tubing is commonly used on automotive wiring harnesses, battery terminals, and connector boots. The glue lining bonds to the wire jacket and connector body, providing strain relief and protection against vibration, moisture, and corrosion — all common challenges in engine bay environments.

The 1m (≈39") length is ideal for single repairs, small projects, or when you need just a short section for a specific connector or splice. The 5m (≈196") length offers better value per meter for larger wiring projects, production runs, or when you anticipate multiple uses of the same diameter and color.

This tubing is generally compatible with PVC, XLPE, and most standard wire insulation materials. The adhesive liner bonds well to smooth, clean surfaces. For specialty insulation materials such as PTFE or silicone-jacketed wire, adhesion may vary — contact us to confirm compatibility before ordering.

Slide the tubing over the wire or connector before making any connections. Position it centered over the area to be sealed. Apply heat evenly using a heat gun, starting from the center and working outward to prevent air pockets. In most cases, you will see the adhesive begin to flow from the ends of the tube — this indicates a good seal has formed. Allow to cool before handling.