3:1 Dual Wall Adhesive Lined Heat Shrink Tubing — φ1.6mm to φ15.4mm, Multiple Colors

Measure the outer diameter of the wire or connector before shrinking. Choose a size where the expanded inner diameter is slightly larger than your wire — typically 10–20% larger. After shrinking at a 3:1 ratio, the tubing will compress tightly around the wire. For example, a φ4.8mm tube generally suits wires up to about 4mm OD. See the size-to-AWG guide in the specs table above for a quick reference.

A 3:1 shrink ratio means the tubing shrinks to one-third of its original diameter, providing a tighter, more secure fit than standard 2:1 tubing. This is especially useful for covering connectors, solder joints, or irregular shapes where a snug grip is critical. The dual wall construction with an inner adhesive layer also creates a waterproof seal that 2:1 single-wall tubing typically cannot provide.

Yes. The inner adhesive (hot-melt glue) layer melts during shrinking and flows around the wire or connector, creating a moisture-resistant seal. This makes it generally suitable for outdoor wiring, marine environments, and automotive applications where moisture protection is needed. For full submersion applications, contact us to confirm suitability.

Dual wall adhesive heat shrink tubing typically requires a heat source of around 120–150°C (248–302°F) to activate the adhesive and begin shrinking. A heat gun is recommended for even, controlled heating. Move the heat gun slowly along the length of the tubing from one end to the other to avoid air pockets. Avoid open flames, which can cause uneven shrinkage or scorching.

Yes. The adhesive-lined construction provides a waterproof, corrosion-resistant seal that is generally well-suited for outdoor wiring, automotive wire harnesses, marine cable protection, and other environments exposed to moisture, vibration, or UV light. The flexible polyolefin outer wall resists cracking in vibration-heavy environments like engine bays. Confirm the specific operating temperature range for your application before use.

As a general guide based on typical wire OD ranges:

• φ1.6mm — typically fits 26–22 AWG wires
• φ2.4mm — typically fits 22–18 AWG wires
• φ3.2mm — typically fits 18–16 AWG wires
• φ4mm — typically fits 16–14 AWG wires
• φ4.8mm — typically fits 14–12 AWG wires
• φ6.4mm — typically fits 12–10 AWG wires
• φ7.9mm — typically fits 10–8 AWG wires
• φ9.5mm — typically fits 8–6 AWG wires
• φ12.7mm — typically fits 6–4 AWG wires
• φ15.4mm — typically fits 4–2 AWG wires

Always measure your wire's actual outer diameter to confirm the right size.

No. All color options — black, white, red, green, yellow, blue, transparent, and orange — share the same 3:1 shrink ratio and adhesive-lined construction. Color choice is typically used for wire identification, color-coding circuits, or aesthetic preference. Transparent tubing allows you to visually inspect the connection after shrinking.