Red Heat Shrink Tubing 2:1 — 0.6mm to 12mm Diameter, 1M to 30M Lengths

Select a diameter that is slightly larger than the bare wire or connector you need to cover. With a 2:1 shrink ratio, the tubing will shrink to approximately half its listed diameter when heat is applied. For example, a 4.0mm tube will shrink to roughly 2.0mm (≈0.08"). As a general rule, choose a pre-shrink diameter that is 20–30% larger than the object being covered to ensure a snug, secure fit.

A 2:1 shrink ratio means the tubing will shrink to approximately half its original inner diameter when heated. For example, a 6.0mm (≈0.24") tube will typically shrink down to around 3.0mm (≈0.12"). This ratio is the most common for general-purpose wire insulation and cable sleeving applications.

Polyolefin heat shrink tubing generally begins to shrink at around 70–90°C (158–194°F) and achieves full shrinkage at approximately 120°C (248°F). A heat gun is the recommended tool. Avoid open flames, as they can scorch or unevenly shrink the tubing and may damage the underlying wire insulation.

Polyolefin heat shrink tubing is generally resistant to UV exposure, moisture, and mild chemicals, making it suitable for many outdoor and semi-exposed applications such as garden lighting wiring or trailer connectors. However, for harsh marine or direct-burial environments, an adhesive-lined (3:1) variant is typically recommended for a fully waterproof seal.

The range of diameters (0.6mm–12mm) covers a wide variety of wire gauges. As a general guide: 0.6mm–1.5mm suits very fine wires (typically 28–22 AWG), 2.0mm–4.0mm suits 20–14 AWG, and 5.0mm–12mm suits heavier cables, connectors, and bundled wire groups. Always measure the bare wire or bundle outer diameter before selecting a size.

Polyolefin heat shrink tubing is generally manufactured to be flame-retardant, meaning it will self-extinguish when the ignition source is removed. This makes it suitable for automotive wiring, electronics, and other applications where fire safety is a consideration. Contact us to confirm specific compliance certifications for your application.

Yes. Red heat shrink tubing is commonly used in automotive wiring harnesses, trailer wiring, and 12V electrical repairs. The red color is often used to identify positive leads or high-current circuits. Once shrunk, the tubing provides insulation, strain relief, and protection against abrasion and moisture — all important in under-hood and under-dash environments.

For a single splice or connector repair, a 1M (≈3.3 ft) length is typically more than sufficient. For a full automotive wiring harness or a workshop stock supply, the 10M (≈32.8 ft) or 30M (≈98.4 ft) options offer better value per meter. In most cases, cut pieces slightly longer than the area you need to cover, as the tubing shrinks in length by approximately 5–10% as well as in diameter.