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.
Verified Buyer · Verified Purchase★ Verified
3:1 Dual Wall · 10ft Short Pack
3/4"
3:1 Heat Shrink
Fits3/0–4/0 AWG19.1mm
3/4 inch heat shrink tubing fits 3/0–4/0 AWG cable and is the size most installers reach for when sealing a lug crimped onto 2 AWG, where barrel and palm together exceed 15mm. ABYC E-11 Table XI rates 3/0 AWG at 175A and 4/0 AWG at 200A — shore power inlets, main inverter feeds, and starter cable. At 19.1mm expanded, the tube clears bare 3/0 and 4/0 conductors and recovers to roughly 6.4mm, tight enough to grip the cable jacket behind a lug. Apply heat from the lug end toward the cable so trapped air escapes ahead of the shrink and the adhesive is driven down the joint rather than back into the barrel. UL 224, 600V, -55°C to +125°C. Ten feet is a practical amount for a shore power or battery bank job needing six to eight terminations at this diameter.
★★★★★4.7 · 225 verified ratings across the Helixal range
26 in stock · Ships in 24h
Order up to 26 online · need more? Trade pricing
Size3/4" · 19.1mm
Click any size to navigate · 10 ft per roll
$8.9910 ft spool
→ Dispatched within 24 hours — delivered in 1–3 days→ 30-day money-back guarantee — 30 days to return it
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SKU: B0FJNVR7VW · 3/4" (19.1mm) · 10 ft
Spec Sheet
3/4"
data sheet.
Full industrial dual-wall adhesive spec in a convenient 10ft pack. Same 600V rated, waterproof polyolefin construction as the large bulk rolls.
Imperial Size
3/4"
Expanded diameter
Metric Size
19.1mm
Nominal
Roll Length
10 ft
Per spool
Wire Gauge
3/0–4/0 AWG
Bare conductor
Shrink Ratio
3:1
Dual wall
Construction
Dual Wall
Adhesive inner liner
Inner Layer
Hot Melt Adhesive
Waterproof seal
Voltage Rating
600V AC
UL 224 — 600 V rms
Temp Rating
-55°C to +125°C
Continuous service
Shrink Temp
100°C (212°F)
Shrinking starts
Adhesive Flow
120°C (248°F)
Keep heating until it shows
Material
Polyolefin
Outer sleeve
Flammability
Self-extinguishing
UL 224 Recognized
Color
Black
Standard finish
Standards
UL 224 Recognized
UL file E361230 · RoHS
UV Resistance
Yes
Outdoor safe
Waterproof
Yes — adhesive seal
360° coverage
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.
What the
trade says.
Verified Buyers ★ · Full Range4.7★★★★★225 ratings · 84% 5-starCombined verified-buyer rating for every Helixal product — all ratios, all sizes — not this size alone.
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.
R Davis · Verified Purchase★ Verified
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.
Travis M. · Verified Purchase★ Verified
Customer Reviews
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Sizing & Application — 3/4 inch, 10ft pack
Shore power inlet, six terminations, and a heat gun pointed the right way.
3/4 inch (19.1mm) is the size that goes over a lug crimped onto 2 AWG, where barrel and palm together exceed 15mm. It also fits bare 3/0–4/0 AWG, rated by ABYC E-11 Table XI at 175A and 200A. A shore power inlet replacement is six to eight terminations at this diameter — about three feet — and the thing that most often spoils it is not the size but the technique.
Why a large tube is heated from one end and not the middle
A 19.1mm tube encloses a substantial volume of air. Start the heat in the middle and both ends close first, sealing that air inside. The trapped pocket resists the wall coming down, so the tube finishes with a soft bulge that never fully recovers, and the adhesive is pushed outward into the barrel rather than along the joint.
Work from the lug end toward the cable instead. The shrink front then advances in one direction with the open cable end venting ahead of it, and the adhesive is carried down the joint by the closing wall. The finish line is a bead appearing at the cable end, which confirms the liner reached flow temperature through the full length.
Keep the gun moving and rotate the assembly throughout. At this wall thickness the outer surface reaches recovery temperature well before the liner behind it does, so holding the gun still scorches the polyolefin while the adhesive underneath is still stiff. Even heat over slightly longer is what produces a seal rather than a cover.
3/4 inch short pack at a glance
| 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 | Vents air ahead of the shrink and drives adhesive down the joint |
| Shore power job | 6–8 terminations, ≈3 ft | One pack per job, restocked as it empties |
| Bulk equivalent | 30 ft roll | Three jobs — the roll is for someone doing this regularly |
A wrinkled shoulder at the lug is the signature of heat applied in the middle first. It indicates trapped air, and usually a void under the wrinkle.
When to size or buy differently
01 · The assembly has a moulded boot
A finished shore power assembly can exceed a 19.1mm bore. Measure the assembly at its widest and move to the 1 inch pack if it is close.
02 · The jacket is under 7mm
A 6.4mm recovered wall will not grip it and the tube will slide along the cable. Step down to the 5/8 inch pack.
03 · You do this work weekly
The 30ft roll is the right economics at that rate. The pack is for the boat owner or the occasional inlet replacement.
04 · Above 600V
Rated 600V rms. Heavy-wall cable splice tubing is a separate product class and is commonly marketed at 1000V. Do not read a flexible tubing rating as a splice-kit rating.
Keep reading →3/4" 3:1 Dual Wall — 30ft bulk roll · Waterproof Electrical Connectors Guide · Best Heat Shrink for Marine Wiring
How it shrinks.
01
Measure & Select
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.
02
Cut & Thread
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.
03
Apply Heat
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.
04
Inspect
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.
Watch
All Videos →See 3/4" In Use
Size ReferenceExpanded vs.
Expanded vs.
recovered.
Actual 3/4" tube at full expanded diameter (19.1mm) and after heat recovery. Use this as your fit reference before cutting.
Expanded: 19.1mm — slides over 3/0–4/0 AWG
Shrink ratio: 3:1 on full heat
Use it on.
01
Try Before You Buy Bulk
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.
02
Field Repair Kits
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.
03
Stock Multiple Sizes Cheap
For the same cost as one large roll, stock several different sizes in short packs. Covers more connector diameters for the same investment.
04
Marine & Outdoor Spot Repairs
Seals individual connections on boat wiring, outdoor electrical, and trailer harnesses. Same waterproof adhesive seal as the large rolls — just 10ft.
05
Low-Volume Production
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.
06
One-Off Automotive Builds
Custom automotive and motorcycle builds often need several sizes in small quantities. Short rolls let you match every connection without leftover material.
Size Guide
3/4" Questions.
Technical Guides
All Guides →From the Blog
Free Tool
Heat Shrink Size Calculator
Read Guide →Ratios2:1 vs 3:1 vs 4:1 Heat Shrink Ratio Guide
Read Guide →Complete GuideHeat Shrink Tubing: The Complete Guide
Read Guide →SizingSize Chart & Selection Guide
Read Guide →How-ToHeat Shrink for Battery Terminals
Read Guide →AutomotiveAutomotive Wire Protection Guide
Read Guide →Also available — 3/4" in other lines
All 13 sizes.
View line overview →3/32"2.4mm10 ft1/8"3.2mm10 ft3/16"4.8mm10 ft1/4"6.4mm10 ft5/16"8mm10 ft3/8"9.5mm10 ft1/2"12.7mm10 ft5/8"16mm10 ft
Current3/4"19.1mm10 ft
1"25.4mm10 ft1-1/4"31mm10 ft1-1/2"38mm10 ft2"50.8mm10 ftRecovered diameter is approx. 1/3 of the expanded size shown · All sizes ship to USA & Canada