Better than electrical tape by far!
Used this on vehicles (starters) and trailer lights. Easy to use, looks like a professional fitting, and seems to hold tight.
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Helixal — Professional Heat Shrink Tubing
Helixal — Professional Heat Shrink Tubing
3/8 inch heat shrink tubing fits 6–8 AWG wire and is the correct size for sealing a crimped 16–14 AWG butt splice, whose barrel measures 7–8mm. ABYC E-11 Table XI rates 8 AWG at 40A and 6 AWG at 55A — alternator leads, fuse-holder tails, and shore power feeds. At 9.5mm expanded, the tube clears bare 6 and 8 AWG conductors and recovers to about 3.2mm. Here is the sizing rule most charts skip: choose the tube from the widest point it must pass over, then confirm the recovered diameter is smaller than the narrowest thing it must grip. 3/8 inch satisfies both conditions across an unusually wide range, which is why it is the most-ordered size in this line. The hot-melt liner flows at 120°C, filling the step between an oversized barrel and a thin conductor. UL 224, 600V, -55°C to +125°C.
Click any size to navigate · 10 ft per roll
SKU: B0FJN2SZ3H · 3/8" (9.5mm) · 10 ft
Full industrial dual-wall adhesive spec in a convenient 10ft pack. Same 600V rated, waterproof polyolefin construction as the large bulk rolls.
Sizing over a connector? The Wire Gauge row above is for bare conductor. Heat shrink must be sized to the widest point it passes over, so a crimped butt splice or lug barrel needs a larger tube than the wire alone — a 22–18 AWG splice barrel measures 5–6mm, a 16–14 AWG barrel 7–8mm, and a 12–10 AWG barrel 9–11mm. Measure the barrel, allow about 20% clearance, and confirm the recovered diameter is smaller than the narrowest thing the tube must grip. Use the size calculator.
Better than electrical tape by far!
Used this on vehicles (starters) and trailer lights. Easy to use, looks like a professional fitting, and seems to hold tight.
Good quality and sealing heat shrink
Heat shrink works good. Makes a nice sealed wire connection. Better than pre-cut heat shrink — you can make whatever length you want.
Smart format for repair work
Great for keeping several sizes on hand without the bulk. Same quality as the large rolls — the adhesive seals perfectly every time.
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Verify the expanded diameter is 20–30% larger than your wire or connector. The tubing must slide freely before heat is applied — if it drags, go one size up.
Cut to length and thread onto the wire or cable before making the splice or crimp. Overlap each terminal or connector end by at least 10mm for a proper seal.
Use a heat gun at 120°C or higher. Start at the center and work outward to push air toward the ends. Adhesive will appear at the tube ends — that is your visual seal indicator.
The tubing should be tight and uniform with adhesive visible at both ends. No gaps, lifting, or cold spots. Pull-test the finished connection to confirm the adhesive bond.
Actual 3/8" tube at full expanded diameter (9.5mm) and after heat recovery. Use this as your fit reference before cutting.
Order a 10ft pack to verify the size fits your connector before committing to a large roll. Test fit, shrink one piece, then buy the bulk roll with confidence.
Keep a set of short rolls on the service van or boat. Enough for any repair job without hauling large rolls — one 10ft roll handles most splices.
For the same cost as one large roll, stock several different sizes in short packs. Covers more connector diameters for the same investment.
Seals individual connections on boat wiring, outdoor electrical, and trailer harnesses. Same waterproof adhesive seal as the large rolls — just 10ft.
Ideal for small-batch cable assembly and prototype builds where a full bulk roll would sit unused. Cost-effective for runs of fewer than 50 connections.
Custom automotive and motorcycle builds often need several sizes in small quantities. Short rolls let you match every connection without leftover material.
Recovered diameter is approx. 1/3 of the expanded size shown · All sizes ship to USA & Canada
