2:1 Heat Shrink Tubing – Gray, φ1mm to φ50mm, 1m / 5m / 10m Lengths

Measure the outer diameter of the wire or connector before shrinking. Choose a tubing size whose expanded inner diameter is at least 10–20% larger than your cable's OD. After shrinking at a 2:1 ratio, the tubing will typically recover to roughly half its expanded diameter. For example, φ6mm tubing generally covers cables up to about 5mm OD and shrinks down to approximately 3mm.

Polyolefin 2:1 heat shrink tubing typically begins to shrink at around 70–90°C (158–194°F) and fully recovers at approximately 120°C (248°F). A heat gun set to low or medium is generally sufficient. Avoid open flames, which can scorch or uneven-shrink the tubing.

Standard polyolefin heat shrink tubing is moisture-resistant and generally suitable for light outdoor use. However, it does not provide a waterproof seal on its own. For fully weatherproof connections, consider adhesive-lined (3:1) tubing instead. This gray tubing is well-suited for indoor wiring, automotive interiors, and protected outdoor enclosures.

A 2:1 shrink ratio means the tubing shrinks to approximately half its original expanded diameter when heat is applied. For example, φ10mm tubing will recover to roughly φ5mm after full shrinkage. This ratio is the most common for general-purpose wire insulation and bundling.

Yes. Polyolefin heat shrink tubing is generally flame-retardant and provides electrical insulation. It is commonly used to insulate wire splices, solder joints, and terminals in automotive, marine, and electronics applications. Always verify the voltage rating for your specific application.

Yes. Gray 2:1 heat shrink tubing is widely used in automotive wiring harnesses, marine cable management, and electronics repair. It resists common automotive fluids and provides a clean, professional finish. For marine or fully submerged use, adhesive-lined tubing is generally recommended.

Use sharp scissors or a utility knife to cut the tubing before applying heat. Cut slightly longer than needed — typically 5–10mm extra on each end — to allow for any longitudinal shrinkage that may occur during the heat-shrink process.