Heat Shrink Tubing 2:1 Ratio — Electrical Wire Sleeving, φ60mm–φ210mm, 7 Colors

Measure the outer diameter (OD) of the cable bundle, connector, or pipe you need to cover. The tubing's recovered diameter (approximately half the listed size) should be slightly smaller than your object's OD for a snug fit. For example, φ80mm tubing (≈3.15" supplied) typically recovers to ~φ40mm (≈1.57"). If your bundle measures 35mm OD, φ80mm is a good fit. When in doubt, size up — a slightly larger tube will still shrink down evenly.

A 2:1 ratio means the tubing shrinks to approximately half its original supplied diameter when heat is applied. So φ100mm (≈3.94") supplied becomes roughly φ50mm (≈1.97") recovered. This is the most common ratio for general-purpose electrical insulation, bundling, and strain relief applications.

Polyolefin heat shrink tubing generally begins to activate at around 90°C (194°F) and fully recovers at approximately 120°C (248°F). A heat gun set to medium-high is the recommended tool. Move the heat gun evenly along the tubing to avoid hot spots. Open flames are not recommended — they can cause uneven shrinkage, scorching, or discoloration.

Standard polyolefin heat shrink tubing is generally moisture-resistant and suitable for sheltered outdoor use — for example, under a vehicle hood or in a covered electrical panel. It is not waterproof or rated for submersion. For fully weatherproof or marine applications where water ingress is a concern, adhesive-lined (3:1) tubing is typically a better choice. Contact us to confirm suitability for your specific environment.

Yes — this large-diameter range (φ60mm–φ210mm) is specifically suited for bundling multiple cables, covering large automotive or marine connectors, providing strain relief on thick cable assemblies, and insulating pipe joints or conduit ends. It is not designed for individual small-gauge wires (for those, standard 3mm–25mm tubing is more appropriate). Always verify the recovered diameter against your connector or bundle OD before ordering.

Polyolefin heat shrink tubing in this category generally provides electrical insulation suitable for low-voltage applications, typically up to 600V in standard configurations. It is not intended as primary insulation for high-voltage power systems. For specific dielectric strength or UL/RoHS compliance requirements, contact us to confirm before ordering.

The "Length" option on this product refers to quantity per order: selecting "1" gives you a single tube section in your chosen size and color, while "5" gives you a pack of five identical sections. The 5-pack offers a lower per-unit cost and is ideal for workshop stock, multi-cable projects, or when you need matching sleeves across several connections.

In most cases, yes — polyolefin heat shrink tubing can generally be cut to length with sharp scissors or a utility knife before applying heat. Cut cleanly and squarely to avoid fraying. The tubing will shrink radially (in diameter) when heated, with minimal longitudinal shrinkage in most standard formulations. Contact us to confirm the specific tube length included per piece if you need to plan cuts in advance.