Heat Shrink Tubing 2:1 / 3:1 / 4:1 — Φ0.6mm to Φ50mm, 7 Colors, Adhesive & Non-Adhesive

Measure the outer diameter of the wire or connector you need to cover, then select a tubing size that is slightly larger before shrinking. For example, if your wire bundle is 4mm across, choose Φ5mm or Φ6mm tubing. After heat is applied, the tubing will shrink to approximately half (2:1), one-third (3:1), or one-quarter (4:1) of its original diameter depending on the ratio you select.

The ratio describes how much the tubing shrinks in diameter when heat is applied. A 2:1 ratio shrinks to half its original size — suitable for standard wire insulation. A 3:1 ratio (with adhesive liner) shrinks to one-third and provides a waterproof seal, ideal for marine or outdoor use. A 4:1 ratio (with adhesive liner) offers the tightest fit and strongest moisture barrier, commonly used for heavy-duty cable protection and irregular shapes like T-splices or terminal ends.

The 3:1 and 4:1 variants include an inner adhesive lining that melts and flows when heated, creating a moisture-resistant seal around the wire or connector. These are generally suitable for outdoor, marine, and automotive applications where moisture ingress is a concern. The 2:1 non-adhesive version provides electrical insulation but is not rated as a waterproof seal.

Most polyolefin heat shrink tubing typically activates at around 90°C (194°F) and fully shrinks at approximately 120°C–150°C (248°F–302°F). A heat gun is the recommended tool for even, controlled shrinking. Avoid open flames as they can scorch or unevenly shrink the tubing. Contact us to confirm exact activation temperatures for your selected size and ratio.

Yes. With sizes ranging from Φ0.6mm to Φ50mm, this tubing is generally compatible with wire gauges from AWG 30 down to large cable bundles and connectors. The 3:1 and 4:1 adhesive-lined options are also well-suited for irregular shapes such as T-splices, butt connectors, and terminal ends where a standard 2:1 tube may not conform tightly enough.

Choose based on the total length of wire or cable you need to cover. For single repairs or short connection points, 1M (≈39") is typically sufficient. For wiring harnesses or multiple connections in one project, 2M (≈79") or 5M (≈197") rolls offer better value. Note that larger diameter sizes (Φ16mm and above) are generally available in 1M or 2M lengths only.

No — color is purely for identification and organization purposes. All seven color options (Black, White, Red, Green, Yellow, Blue, Clear) share the same electrical insulation and shrink performance within each ratio type. Clear tubing is particularly useful when you want to see the underlying wire color or a printed label after shrinking.