White 2:1 Heat Shrink Tubing – Φ0.6mm to Φ80mm | Wire Cable Sleeving

Measure the outer diameter of the wire, connector, or bundle you need to cover. Choose a tubing size whose unshrunk (pre-shrink) inner diameter is at least 20–30% larger than your bundle. With a 2:1 shrink ratio, the tubing will shrink to approximately half its listed diameter. For example, Φ6mm tubing (unshrunk) will shrink to roughly Φ3mm (≈0.12"). When in doubt, size up — tubing that is slightly too large will still shrink and conform; tubing that is too small won't fit over the connector at all.

A 2:1 shrink ratio means the tubing will shrink to approximately half its original inner diameter when heat is applied. So Φ10mm (≈0.39") tubing will recover to roughly Φ5mm (≈0.20"), and Φ25mm (≈0.98") tubing will shrink to roughly Φ12.5mm (≈0.49"). This ratio applies to the diameter — the length will also shorten slightly (typically 5–10%) during shrinking.

This polyolefin 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 standard heat gun set to low or medium is generally sufficient. Move the heat gun slowly and evenly along the tubing to avoid scorching. Avoid using open flames directly on the tubing, as this can cause uneven shrinking or discoloration.

This standard 2:1 polyolefin tubing provides basic moisture resistance and is generally suitable for light outdoor use and splash protection. However, it is not waterproof — it does not have an adhesive inner lining to create a sealed barrier. For fully waterproof or submersible applications, we recommend adhesive-lined (3:1 or 4:1) heat shrink tubing, which creates a watertight seal when shrunk.

Yes. This tubing is made from flame-retardant polyolefin that is self-extinguishing — it will not continue to burn once the heat source is removed, and it generally meets UL VW-1 or equivalent flame-retardant standards. It is widely used for automotive wire splice insulation, connector protection, and harness wrapping, and typically withstands the temperature ranges found in most under-hood environments.

Yes. For bundling, measure the total outer diameter of the wire group when held together, then select a tubing size whose unshrunk diameter is at least 20–30% larger than that measurement. The larger diameter sizes (Φ20mm–Φ80mm) are particularly well-suited for cable harness bundling, conduit sleeving, and protecting multi-conductor cable runs in automotive, marine, and industrial settings.

In most cases, cut the tubing so it extends at least 10–15mm (≈0.4–0.6") beyond each end of the splice or connector. This ensures full coverage and prevents the tubing from pulling back from the joint during shrinking. For larger connectors or strain relief applications, a longer overlap of 20–30mm (≈0.8–1.2") is generally recommended.