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Maximum protection. The inner adhesive liner melts and seals every gap — creating a connection that water, fuel, and corrosion cannot reach.
Shrink Ratio
3:1
Construction
Adhesive-Lined
Voltage Rating
600V
Available Sizes
13 Sizes
Roll Length
20–60 ft
Product Overview
Helixal 3:1 dual wall heat shrink tubing is the professional's choice when a connection must remain sealed for years. The outer polyolefin sleeve shrinks to one-third of its original diameter, while the inner hot-melt adhesive liner flows into every crevice — bonding to the wire, connector, and insulation alike.
The result is a joint that is mechanically protected, electrically insulated, waterproof, and strain-relieved in a single operation. No tape. No re-work. No callbacks.
The hot-melt adhesive inner layer flows when heated, filling every gap and creating a hermetic seal that water, fuel, and oils cannot penetrate.
Meets the demands of automotive, marine, and industrial electrical systems. Rated to 600V for confident use in demanding environments.
Formulated to withstand long-term UV exposure without cracking or becoming brittle — essential for outdoor and marine installations.
Dual-wall design with polyolefin outer sleeve and hot-melt adhesive inner liner. 3:1 shrink ratio ensures a tight fit even on irregular shapes.
Rated from -55°C to +125°C. Performs in arctic cold, engine bays, and industrial heat environments without degradation.
Manufactured to MIL-DTL-23053/4 specification — the same standard used in aerospace, defense, and naval applications.
How It Works
No specialist tools. No guesswork. Reliable waterproof connections every time.
Position the tubing over the connection before crimping or soldering. Leave at least 6mm overlap on both sides past the connection point.
Works with connectors, terminals, splices, and bare wire ends.
Use a heat gun at 120°C–175°C. Move evenly along the length side-to-side — avoid holding in one spot. The tubing shrinks quickly and uniformly.
A standard 300W heat gun is sufficient. Never use an open flame.
The adhesive liner melts and flows into every gap around the wire and terminal. On cooling it forms a rigid waterproof bond that won't loosen or crack.
Rated for saltwater submersion and continuous vibration.
For the best adhesive flow on 3:1 dual wall tubing, start heat at the center of the joint and work outward toward each end — this pushes trapped air out and ensures the adhesive fills every gap before setting.
Order by Size
All sizes ship directly from Amazon. Recovered diameter is approximately 1/3 of supplied diameter.
| Size (Imperial) | Size (mm) | Roll Length | View / Buy |
|---|---|---|---|
| 3/32" | 2.4mm | 60 ft | 3/32" — 60 ft |
| 1/8" | 3.2mm | 60 ft | 1/8" — 60 ft |
| 3/16" | 4.8mm | 60 ft | 3/16" — 60 ft |
| 1/4" | 6.4mm | 60 ft | 1/4" — 60 ft |
| 5/16" | 8mm | 60 ft | 5/16" — 60 ft |
| 3/8" | 9.5mm | 60 ft | 3/8" — 60 ft |
| 1/2" | 12.7mm | 60 ft | 1/2" — 60 ft |
| 5/8" | 16mm | 30 ft | 5/8" — 30 ft |
| 3/4" | 19.1mm | 30 ft | 3/4" — 30 ft |
| 1" | 25.4mm | 30 ft | 1" — 30 ft |
| 1-1/4" | 31mm | 20 ft | 1-1/4" — 20 ft |
| 1-1/2" | 38mm | 20 ft | 1-1/2" — 20 ft |
| 2" | 50.8mm | 20 ft | 2" — 20 ft |
Technical Data
Size Reference
Applications
Why Heat Shrink
| Feature | Heat Shrink (HELIXAL) | Electrical Tape |
|---|---|---|
| Waterproof | Yes — adhesive liner seals completely | No — water seeps under with age |
| Permanent Fit | Heat-shrunk, cannot unravel | Loosens over time, especially in heat |
| Durability | 10+ years in harsh environments | 1–3 years typical service life |
| Temperature Range | -55°C to +125°C | Limited — melts above 80°C |
| Professional Look | Clean, finished appearance | Bulky, uneven wrapping |
| Cost Over Time | One application, done | Frequent re-wrapping adds up |
FAQ
Dual wall heat shrink tubing has two layers: an outer polyolefin wall that shrinks with heat, and an inner hot-melt adhesive liner. When heated, the adhesive flows and creates a waterproof, strain-relieving seal around the wire or connector. It is the preferred choice for heat shrink butt connectors and waterproof wire splices.
The ratio describes how much the tubing shrinks in diameter. 2:1 tubing shrinks to half its original diameter. 3:1 tubing shrinks to one-third — giving you more flexibility to cover connectors, terminals, and irregular shapes while still fitting over thicker wires.
Yes. The inner adhesive liner melts at around 70°C and flows into voids and threads, creating a watertight seal rated for marine and outdoor environments. It meets requirements for bilge pump wiring, trailer harnesses, and saltwater applications.
Helixal dual wall tubing begins shrinking at around 70°C (158°F) and fully activates the adhesive liner at 120–150°C (250–300°F). A standard heat gun set to 300–350°C works perfectly. Avoid open flames which can scorch the tubing.
Cut the tubing about 20–30% longer than the area you need to cover, as it will shrink slightly in length as well as diameter. For wire splices, cover at least 1 inch on each side of the joint.
Ready to Order?
All 13 sizes available now on Amazon. Prime eligible. Or contact us directly for wholesale pricing and trade accounts.