Black Heat Shrink Tubing 2:1 — φ13mm to φ210mm Wire Cable Sleeve

Measure the outer diameter of your wire, cable bundle, or connector. Choose a heat shrink size where the listed diameter is at least 10–20% larger than your cable. With a 2:1 shrink ratio, the tubing will shrink to approximately half its listed diameter after heat is applied. For example, 20mm (3/4") tubing will shrink down to approximately 10mm. When in doubt, size up — a slightly oversized tube will still shrink down tightly and produce a clean finish.

This tubing has a 2:1 shrink ratio, meaning it shrinks to approximately half its original expanded diameter when heat is applied evenly. The listed diameter is the pre-shrink expanded size. For example, 50mm (2") tubing will shrink to approximately 25mm (1") after heating. Always measure your cable or connector before selecting a size to ensure a snug, secure fit after shrinking.

Standard 2:1 polyolefin heat shrink tubing is generally moisture-resistant and suitable for light outdoor use. The black color also provides UV resistance for prolonged outdoor exposure. It provides a protective barrier against dust, light moisture, and abrasion. For full waterproofing, submersion, or direct burial applications, adhesive-lined (3:1 or 4:1) heat shrink tubing is typically recommended instead. Contact us if you need guidance for a specific outdoor application.

A heat gun is recommended for even, controlled shrinking. Apply heat in a slow, sweeping motion along the length of the tubing, working from the center outward to avoid trapping air. For smaller diameters (13–25mm), a lighter or hair dryer on its highest setting may work in a pinch, but a heat gun gives the most consistent results. For larger diameters (60mm and above), a heat gun is strongly recommended to ensure even shrinkage without scorching.

Polyolefin heat shrink tubing generally provides solid electrical insulation suitable for low- to medium-voltage wire and cable applications. It is widely used in automotive wiring harnesses, marine electrical systems, and electronics projects. For high-voltage or industrial applications where specific dielectric ratings are required, contact us to confirm suitability for your use case before ordering.

Yes. Black 2:1 heat shrink tubing is one of the most widely used materials for automotive wiring harness repair, marine cable protection, and DIY electronics projects. It is generally compatible with standard copper and aluminum wire conductors. The black color is particularly suited for underhood automotive applications and outdoor cable runs where UV resistance and a clean appearance are both important.

For most wire splice or connector insulation applications, 50–100mm (2–4 inches) of tubing per joint is typically sufficient. For longer cable runs or full harness sleeving, calculate the total length needed and add 10–15% for trimming and positioning. The 0.1M (4") and 0.2M (8") options are ideal for single joints or small repairs; the 1M, 3M, and 5M lengths are better suited for larger wiring projects or keeping stock on hand for future use.