Heat Shrink Tubing 20cm — Reliable Wire Insulation & Cable Protection for Every Project
Whether you're rewiring a car stereo, repairing a frayed extension cord, or tidying up a control panel, exposed wire joints and bare connectors are a safety hazard you can't ignore. Electricians, automotive technicians, hobbyists, and DIYers all face the same challenge: finding heat shrink tubing that fits a wide range of cable sizes without ordering from a dozen different listings.
Each piece in this listing is 20cm (≈7.9") long and is made from polyolefin — a flexible, low-odor material that shrinks to a tight, uniform fit at a 2:1 ratio. Diameter options span from Φ20mm (≈0.79") to Φ210mm (≈8.27"), covering everything from thin signal wires to large cable bundles and conduit ends. Available in Transparent and Black, with packing quantities of 1, 2, 5, or 10 pieces per order.
Typical use cases include automotive wiring harness repair, marine cable splicing, electrical panel wire management, DIY electronics projects, and protecting soldered joints on battery packs. The wide diameter range makes this a go-to solution for both fine gauge wire insulation and large-diameter cable sleeve protection.
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Compatible with: Copper wire, aluminum wire, coaxial cable, multi-conductor cable, battery leads, terminal connectors, and most round cable profiles. Suitable for automotive, marine, industrial, and household electrical applications.
✅ Key Features of These Heat Shrink Tubing Sleeves
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Wide Diameter Range — Covers Φ20mm to Φ210mm in a single product line, so you can find the right fit for thin signal wires, thick power cables, and large conduit ends without switching suppliers.
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2:1 Shrink Ratio — Shrinks to half its original inner diameter when heat is applied, creating a snug, uniform sleeve that conforms tightly to irregular cable shapes and connector bodies.
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Polyolefin Construction — Flexible, low-odor polyolefin material provides electrical insulation, abrasion resistance, and protection against moisture — a reliable choice for automotive wiring harness repair and marine cable splicing.
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20cm Pre-Cut Length — Each piece is cut to 20cm (≈7.9"), long enough to cover most connector-to-wire transitions and splice points without wasting material on short repairs.
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Two Color Options — Choose Transparent to keep wire color coding visible through the sleeve, or Black for a clean, professional finish on exposed wiring in engine bays and control panels.
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Flexible Pack Sizes — Order 1, 2, 5, or 10 pieces per variant to match your project scale — from a single quick fix to stocking your workshop with heat shrink wire sleeve supplies.
📐 Technical Specifications — Heat Shrink Tubing 2:1 Ratio
| Material |
Polyolefin |
| Shrink Ratio |
2:1 |
| Length per Piece |
20cm (≈7.9") |
| Diameter Options |
Φ20mm (≈0.79"), Φ25mm (≈0.98"), Φ28mm (≈1.10"), Φ30mm (≈1.18"), Φ35mm (≈1.38"), Φ40mm (≈1.57"), Φ45mm (≈1.77"), Φ50mm (≈1.97"), Φ60mm (≈2.36"), Φ70mm (≈2.76"), Φ80mm (≈3.15"), Φ120mm (≈4.72"), Φ180mm (≈7.09"), Φ210mm (≈8.27") |
| Color Options |
Transparent, Black |
| Packing Quantity |
1 pc, 2 pcs, 5 pcs, 10 pcs (per variant) |
| Shrink Temperature |
Typically 120°C (248°F) full recovery; begins shrinking at approx. 70–90°C (158–194°F) |
| Voltage Rating |
Typically up to 600V — contact us to confirm for your application |
| Application |
Wire insulation, cable splicing, connector protection, strain relief |
| Suitable Environments |
Automotive, marine, industrial, household electrical |
| Minimum Recovered ID |
See variant options (approx. 50% of listed diameter) |
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Size tip: Measure your cable or connector outer diameter before ordering. Select a tubing diameter that is approximately 20–30% larger than your measured size to ensure the tubing slides on easily before shrinking.
❓ Frequently Asked Questions
How do I choose the right diameter for my wires?
Measure the outer diameter of the wire bundle or connector before shrinking. Choose a tubing diameter that is typically 20–30% larger than the pre-shrink measurement. For example, a 10mm cable bundle generally fits well inside Φ20mm tubing, which shrinks down to approximately 10mm at a 2:1 ratio. For connectors with irregular shapes, size up to the next diameter to ensure the tubing slides over easily.
What does 2:1 shrink ratio mean?
A 2:1 ratio means the tubing shrinks to half its original inner diameter when heat is applied. For example, Φ60mm tubing will shrink down to approximately 30mm (≈1.18"). This ratio is standard for general-purpose electrical insulation and cable management tasks such as wire splicing and connector sealing.
Can this heat shrink tubing be used outdoors or in wet environments?
Polyolefin heat shrink tubing generally offers good resistance to UV exposure, moisture, and mild chemicals, making it suitable for many outdoor applications such as garden lighting wiring and exterior junction boxes. For prolonged direct UV or saltwater exposure — such as on boat wiring — an adhesive-lined variant is typically recommended for a fully sealed, waterproof result.
What temperature is needed to shrink this tubing, and what tools can I use?
Polyolefin heat shrink tubing generally begins to shrink at around 70–90°C (158–194°F) and fully recovers at approximately 120°C (248°F). A heat gun set to low or medium is the recommended tool for even, controlled shrinkage. A lighter can be used carefully for small diameters in a pinch, but may cause uneven shrinkage or scorching on larger sizes.
Is this tubing suitable for automotive and marine wiring?
Yes. Polyolefin heat shrink tubing is commonly used in automotive wiring harness repair, marine cable splicing, and industrial control panel wiring. It provides electrical insulation, abrasion resistance, and strain relief at wire terminations. For marine environments with constant water immersion, an adhesive-lined version is generally preferred to create a watertight seal.
How long is each piece and what packing quantities are available?
Each piece is 20cm (approximately 7.9 inches) long. You can order in packs of 1, 2, 5, or 10 pieces per diameter and color combination. This makes it easy to grab a single piece for a quick repair or stock up for larger wiring projects without over-ordering.
What is the voltage rating of this heat shrink tubing?
Standard polyolefin heat shrink tubing is typically rated for up to 600V. This covers the vast majority of household, automotive, and low-voltage industrial applications. If your application requires a higher voltage rating, please contact us to confirm before ordering.
🛒 Select your diameter, color, and pack quantity above, then add to cart — ships from our US warehouse.
