1.7:1 Silicone Heat Shrink Tubing — Blue, φ1mm to φ12mm

Measure the outer diameter of your wire or cable bundle before shrinking. Choose a tubing size whose unshrunk inner diameter is at least 10–20% larger than your cable OD. With a 1.7:1 shrink ratio, the tubing will shrink to approximately 59% of its original diameter — so a 3mm tube typically recovers to around 1.8mm. When in doubt, size up one step. Quick reference: 1mm (0.04") suits very fine wires; 6mm (0.24") suits 14–12 AWG; 12mm (0.47") suits heavier cables or small bundles.

Silicone heat shrink tubing generally begins to shrink at around 120°C (248°F) and fully recovers by approximately 150–175°C (302–347°F). A heat gun set to medium-high is typically sufficient. Move the heat gun slowly and evenly along the tubing to avoid hot spots. Avoid open flames, which can cause uneven shrinkage or surface scorching.

Yes. Silicone is inherently resistant to moisture, UV exposure, and mild chemicals, making it suitable for outdoor wiring, garden lighting, and environments with occasional water exposure. It does not provide a fully waterproof seal on its own — for submersion or fully sealed applications, consider adhesive-lined heat shrink tubing instead.

Silicone heat shrink tubing generally handles continuous operating temperatures from approximately -60°C (-76°F) up to 200°C (392°F). This makes it well-suited for automotive engine bays, industrial equipment, and high-heat electronics where standard PVC tubing would soften or become brittle over time.

Yes. The diameter range of 1mm–12mm (unshrunk) covers a wide span of wire gauges. As a general guide: 1mm suits very fine wires around 30–28 AWG; 3mm suits 22–18 AWG; 6mm suits 14–12 AWG; 10–12mm suits heavier cables or small bundles. Always verify against your specific cable outer diameter before ordering.

Cut the tubing at least 10–15mm (approximately 1/2") longer than the area you need to cover on each end, as the tubing may shorten slightly lengthwise during shrinking — typically 5–10% axial shrinkage. For connector boots or splice covers, allow extra overlap on both sides for a clean, secure finish.

Silicone heat shrink tubing is a popular choice for automotive and motorcycle wiring harnesses because it withstands engine heat, vibration, and exposure to oils and fluids better than standard PVC alternatives. It remains flexible even at low temperatures, which helps prevent cracking in cold climates — a common failure point with cheaper sleeving materials.

For solder joints, choose a diameter that fits loosely over the largest part of the joint before shrinking. In most cases, going one size larger than what fits your wire alone gives enough clearance to slide the tubing into position, then shrinks down snugly over the joint. For bulkier connectors, measure the connector body OD and select accordingly.