Red Heat Shrink Tubing 2:1 Ratio — Electrical Wire Sleeving & Cable Wrap

Measure the outer diameter of the wire or bundle you need to cover. Choose a pre-shrink diameter that is at least 10–20% larger than your wire OD. With a 2:1 shrink ratio, the tubing will shrink to approximately half its original diameter when heat is applied. For example, Ø6mm tubing will shrink to roughly Ø3mm (≈0.12"). For a wire bundle measuring 4mm across, Ø6mm or Ø7mm tubing would typically be a good starting point.

Polyolefin heat shrink tubing typically activates at around 90°C (194°F) and fully shrinks at approximately 120°C (248°F). A heat gun is generally recommended for even, controlled shrinkage. A lighter or match can work in a pinch but may cause uneven results or scorching on smaller diameters.

Polyolefin heat shrink tubing generally provides solid electrical insulation, typically rated for voltages up to 600V in standard grades. It also offers mechanical protection against abrasion and minor impacts. For high-voltage or industrial applications, please contact us to confirm suitability for your specific requirements.

Standard polyolefin heat shrink tubing offers moderate UV and moisture resistance, making it suitable for many semi-exposed or sheltered outdoor applications such as garden lighting wiring or covered junction boxes. For fully exposed outdoor or marine environments, an adhesive-lined or UV-stabilized variant is generally recommended for long-term durability.

Yes, 2:1 polyolefin heat shrink tubing is widely used in automotive wiring repairs, connector insulation, and harness bundling. It is generally resistant to common automotive fluids such as oil and fuel splatter. For fuel-line or high-heat engine bay applications, confirm the specific temperature rating before use to ensure compatibility.

Measure the total length of wire or splice you need to cover, then add 10–15% extra for trimming and overlap at each end. We offer packing quantities from 1m up to 50m so you can order exactly what your project requires. For a single repair job, 1m or 2m is typically sufficient; for workshop stock or larger harness builds, 10m or 50m rolls offer better value per meter.

Polyolefin heat shrink tubing is typically manufactured to be flame-retardant in accordance with UL 224 or equivalent standards. This means it will generally self-extinguish when the heat source is removed, reducing fire risk in electrical installations. Contact us if you require specific compliance documentation for your application.