2:1 Heat Shrink Tubing — Φ16mm to Φ210mm, Multiple Colors, 1M & 5M Lengths

Measure the outer diameter (OD) of the wire, connector, or bundle you need to cover. Select a tubing size whose recovered (shrunken) diameter is slightly smaller than that OD. For example, Φ16mm tubing shrinks to approximately 8mm. As a general rule, choose a pre-shrink diameter that is 20–30% larger than your cable's OD to ensure a snug, secure fit after shrinking. If you're covering a connector or terminal, measure the widest point of the assembly.

A 2:1 shrink ratio means the tubing will shrink to approximately half its original inner diameter when heat is applied. For example, Φ25mm (≈1") tubing will typically recover to around 12.5mm (≈0.5"). This is the most common ratio for general-purpose electrical insulation, wire bundling, and cable management projects.

Most 2:1 polyolefin heat shrink tubing generally activates at around 90°C (194°F) and fully recovers at approximately 120°C (248°F). A standard heat gun set to low or medium is typically sufficient. Move the heat gun evenly along the tubing to avoid hot spots. Avoid using open flames such as lighters or torches, as these can cause uneven shrinkage, scorching, or damage to the underlying wire insulation.

Standard polyolefin heat shrink tubing generally provides good resistance to moisture, UV exposure, and mild chemicals, making it suitable for many outdoor applications such as garden lighting wiring, automotive harnesses, and marine cable management. For prolonged submersion or harsh chemical environments, we recommend contacting us to confirm the specific ratings before purchase.

Compatibility is based on the cable's outer diameter (OD), not wire gauge alone. As a general guide: Φ16mm suits cables with OD up to approximately 13mm; Φ25mm suits OD up to approximately 20mm; Φ50mm suits OD up to approximately 40mm. For connectors, terminals, or multi-conductor bundles, measure the bundle OD and select accordingly. Contact us to confirm if you have a specific application in mind.

Yes. 2:1 polyolefin heat shrink tubing is widely used in automotive wiring harness repair, connector insulation, and wire bundling. It generally withstands typical engine-bay temperatures and provides reliable insulation against vibration and abrasion. For high-heat zones near exhaust components or turbochargers, a higher-temperature-rated tubing may be more appropriate — contact us to confirm.

Color choice is typically based on wire identification standards or personal preference. Black is the most common for general insulation. Red, Blue, Green, Yellow, and White are often used for color-coded wiring systems — for example, to distinguish positive/negative leads or phase identification in multi-conductor setups. Transparent tubing allows you to see the underlying wire or printed label without removing the sleeve, which is useful for inspection or labeling purposes.