3/4 inch heat shrink tubing fits 3/0 and 4/0 AWG cable — used for RV shore power inlet wiring, marine shore power connections, LiFePO4 main battery feed cables, and large cable bundle exits. ABYC E-11 Table XI rates 3/0 AWG at 175A and 4/0 AWG at 200A; cables at these ratings are the main feed conductors for large inverters, shore power inlets, and high-capacity LiFePO4 battery systems. At 19.1mm expanded diameter, this tube slides freely over 3/0 and 4/0 AWG conductors and recovers to approximately 6.4mm after full heat application. The mechanical strain relief provided by the 3:1 adhesive liner is as important as the waterproof seal at this diameter — the liner bonds to the cable jacket and prevents abrasion and jacket cracking where large cables enter panel knockouts or pass through bulkhead grommets. For indoor dry-area installations where waterproofing is not required, the 2:1 standard is a lower-cost option in this size. The 3/4" size is the standard for shore power cord terminations and main bus connections on large vessels and Class A RVs.
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SKU: B0D647QFF8 · 3/4" (19.1mm) · 30 ft
Complete dual-wall adhesive performance in a bulk roll format. Permanently waterproof, 600V rated, and rated for the harshest environments.
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.
High quality and amazing value for the price
I'll never buy individual bags of heat shrink tubing again. This is very high quality with a shrink ratio that is truly amazing (all of the tubing from this company is). I wonder if I'll be able to use this entire roll in 10 years!
Good quality and sealing heat shrink
Heat shrink works good. Bought this for work. Makes a nice sealed wire connection. Good quality, better than pre cut heat shrink, you can make whatever length you want.
I LIKE THIS!
I solder, and heat shrink, all of my automotive electrical connections. This is a great product, and I can cut it to any length. The price is great, and the shipping was fast!
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3/4 inch (19.1mm) is what most installers reach for over a lug crimped onto 2 AWG, where barrel and palm together exceed 15mm. The cable itself would take 1/2 inch — but the cable is not what the tube has to pass over. It also fits bare 3/0–4/0 AWG, rated by ABYC E-11 Table XI at 175A and 200A: shore power inlets, main inverter feeds, starter cable.
A 19.1mm tube holds a large volume of air, and once the ends begin to close, that air has nowhere to go. Heat the middle first and you seal both ends around a trapped pocket, which shows up as a soft bulge that never fully recovers and a wrinkled shoulder at the lug. The adhesive is pushed outward into the barrel instead of down the joint.
Work from the lug end toward the cable instead. The shrink front then travels in one direction, air escapes ahead of it at the open cable end, and the adhesive is driven along the joint rather than back into the terminal. Stop when a bead appears at the cable end — that bead confirms the liner has flowed the full length.
Keep the gun moving and rotate the assembly as you go. At this wall thickness the outside of the tube reaches recovery temperature well before the adhesive does, so a static gun scorches the polyolefin while the liner underneath is still stiff. Even heat over a slightly longer time is what actually produces the seal.
| Property | Figure | Why it matters |
|---|---|---|
| Expanded diameter | 19.1mm (3/4") | Clears a 2 AWG lug where barrel plus palm exceeds 15mm |
| Recovered diameter | ≈6.4mm | Grips the cable jacket behind the lug |
| Bare cable range | 3/0–4/0 AWG | 175A for 3/0, 200A for 4/0 (ABYC E-11 Table XI) |
| Heat direction | Lug end toward the cable | Drives air out ahead of the shrink and adhesive down the joint |
| Wall type | 3:1 dual wall, hot-melt lined | Seals the shoulder where a shore power inlet corrodes first |
| Roll length | 30 ft | Six to eight terminations per job at 3–4 in each; several jobs per roll |
A bead of adhesive at the cable end is the seal indicator. No bead usually means the liner never reached flow temperature through the full wall.
A finished shore power assembly with a moulded boot can exceed a 19.1mm bore. Measure the assembly, not the cable, and step to 1 inch if it is close.
On an unterminated 3/0 run, 3/4 inch works but is generous. Confirm the recovered 6.4mm actually grips your jacket, or the tube will slide along the cable.
Where the job is strain relief and abrasion rather than sealing, the 3/4" 2:1 on 90ft is the cheaper way to protect a cable entry.
Rated 600V rms. Heavy-wall cable splice tubing is a different product class and is commonly marketed at 1000V; do not read a flexible tubing rating as a splice-kit rating.
Keep reading →5/8" 3:1 Dual Wall — the next size down · Waterproof Electrical Connectors Guide · Best Heat Shrink for Marine Wiring
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.
The tubing starts shrinking at 100°C, but the adhesive liner only flows at 120°C — so keep the heat gun moving past the point where it looks shrunk. 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 3/4" tube at full expanded diameter (19.1mm) and after heat recovery. Use this as your fit reference before cutting.
Seals battery terminal connections in marine, automotive, and RV systems. Adhesive provides mechanical strain relief on large lugs.
Protects high-current winch and anchor windlass wiring from submersion, vibration, and repeated flexing in off-road and marine use.
Used on shore power inlet wiring, generator output connections, and main bus bar terminations on vessels and dockside equipment.
Seals amplifier power feed terminations and large speaker cable connections from moisture in marine and car audio builds.
Provides insulation and mechanical protection on heavy equipment cable terminations and welding lead connections.
Seals bus bar connections, large lug terminations, and cable entry points on industrial switchgear and distribution panels.
Recovered diameter is approx. 1/3 of the expanded size shown · All sizes ship to USA & Canada
