Select a tubing diameter that is larger than the object you need to cover before shrinking. For a 2:1 ratio tube, the recovered diameter is typically half the supplied diameter. For example, a φ25mm (≈1") 2:1 tube will shrink down to approximately 12.5mm (≈1/2"). For 3:1 ratio, a φ25.4mm (1") tube recovers to roughly 8.5mm (≈1/3"). Always measure the widest point of the object and choose a size that gives at least 10–20% clearance before shrinking.

Polyolefin heat shrink tubing generally begins to shrink at around 70–90°C (158–194°F) and achieves full recovery at approximately 120°C (248°F). A heat gun set to low-to-medium heat is typically sufficient. Avoid directing open flames directly onto the tubing, as this can cause uneven shrinkage or surface scorching.

Standard polyolefin heat shrink tubing generally provides good moisture resistance and is suitable for many outdoor applications such as automotive wiring and exterior cable runs. However, for fully waterproof sealing (e.g., submersion or direct water exposure), an adhesive-lined dual-wall heat shrink tubing is recommended. Contact us to confirm the best option for your environment.

Yes, polyolefin heat shrink tubing is generally manufactured to meet flame-retardant standards (typically UL224 or equivalent) and will self-extinguish when the heat source is removed in most cases. For safety-critical or high-voltage applications, please contact us to verify the specific flame-retardancy rating before ordering.

The shrink ratio describes how much the tubing reduces in diameter when heat is applied. A 2:1 ratio means the tubing shrinks to half its original diameter — ideal for standard wire insulation, cable bundling, and strain relief. A 3:1 ratio shrinks to one-third of its original diameter, making it better suited for irregular shapes, connectors, or applications where a tighter fit over a wider size range is needed, such as sealing over stepped connectors or tapered cable ends.

The tubing is available in diameters from φ22mm to φ35mm (approximately 7/8" to 1-3/8"), making it suitable for larger cables, wire harnesses, conduit bundles, battery cables, and hose protection. For smaller gauge wires, we recommend checking our other heat shrink listings for smaller diameter options. Contact us to confirm compatibility with your specific cable size.

Rolls are available in 30m (≈98ft), 40m (≈131ft), 50m (≈164ft), and 200m (≈656ft) lengths. The tubing can be cut to any length with standard scissors or a utility knife before shrinking. The 200m roll is ideal for workshops, electricians, or production environments that need a continuous supply on hand.