Nice product at great price
Was wiring my car and had quite a few smaller wires to crimp and cover. This worked great — shrinks clean and consistent every time.
Church's · Verified Purchase★ Verified
2:1 Single Wall · UL 224 Recognized
1/8"
2:1 Heat Shrink
Fits16–18 AWG3.2mm
1/8 inch heat shrink tubing fits 16–18 AWG wire — the most common gauge range for standard hook-up wire, appliance power leads, automotive interior wiring, speaker wire, and e-bike motor controller outputs. ABYC E-11 Table XI rates 18 AWG at 7A and 16 AWG at 10A in a bundled chassis installation; these two gauges account for the majority of terminal splice and butt connector work in automotive and marine wiring. At 3.2mm expanded diameter, this tube slides freely over 16 and 18 AWG conductors and recovers to approximately 1.6mm. The single-wall 2:1 construction, qualified to UL 224, is the correct choice for dry indoor environments — terminals inside control panels, splices inside junction boxes, and wire harnesses routed through the cabin. For connections routed through an engine bay, trailer junction, or outdoor enclosure, use the 3:1 dual-wall adhesive-lined version to seal the joint against water ingress. At 120 feet per roll, automotive shops and appliance technicians keep a single spool on hand to cover an entire year of repairs without running short.
★★★★★4.7 · 225 verified ratings across the Helixal range
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Size1/8" · 3.2mm
Click any size to navigate · 120 ft per roll
$18.39120 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: B0FJH9NQKX · 1/8" (3.2mm) · 120 ft
Spec Sheet
1/8"
data sheet.
High-volume UL 224 Recognized polyolefin at an honest per-foot cost. The industry standard for band marking, bundling, and dry indoor electrical insulation.
Imperial Size
1/8"
Expanded diameter
Metric Size
3.2mm
Nominal
Roll Length
120 ft
Per spool
Wire Gauge
16–18 AWG
Bare conductor
Shrink Ratio
2:1
Single wall
Construction
Single Wall
No adhesive liner
Adhesive Liner
None
Not waterproof
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
Material
Polyolefin
UL 224 Recognized
Certification
UL 224
Recognized Component
Flammability
Self-extinguishing
UL 224 Recognized
Color
Black
Standard finish
Moisture
Resistant — not sealed
Single wall only
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.
Perfect for bulk workshop use
Bought this for my automotive workshop and the 120ft roll is exactly what I needed. Shrinks consistently and cleanly every time. Much better value than small packs.
Mike R. · Verified Purchase★ Verified
Professional finish every time
Clean black finish, no bubbles or wrinkles when applied correctly. UL listing is important for commercial electrical work — ticks that box too.
James T. · Verified Purchase★ Verified
Customer Reviews
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Sizing & Application — 1/8 inch
Band marking is not decoration. It is the only documentation a harness carries.
1/8 inch (3.2mm) recovers to about 1.6mm and fits bare 16–18 AWG — trailer lighting, appliance leads, speaker runs, 12V accessory circuits. ABYC E-11 Table XI rates 18 AWG at 7A and 16 AWG at 10A bundled. It is the highest-turnover identification size on the site, and identification is a use case that deserves more respect than it usually gets.
What a colour band is actually doing on a harness
A finished harness is opaque. Once conductors are loomed, taped and routed behind trim, the only information available to the next person is what is visible at the ends and at any break-out. If that information is missing, the next fault takes an hour of continuity testing instead of five minutes of tracing.
Bands of coloured tubing at break-outs solve this in a way that a marker pen does not: they survive heat, oil and abrasion, they cannot smudge, and they read the same after ten years in an engine bay. On a trailer harness the convention is worth following exactly — brown for tail, yellow for left stop and turn, green for right, white for ground — because the next person to open it is unlikely to be you.
This is also the case where the absence of an adhesive liner is an advantage rather than a compromise. An identification band is meant to be cut off and replaced when a circuit changes. A hot-melt liner bonds to the insulation and makes removal a scraping job; single-wall tubing slits off cleanly with a knife tip and leaves the conductor as it was.
1/8 inch at a glance
| Property | Figure | Why it matters |
|---|---|---|
| Expanded diameter | 3.2mm (1/8") | Slides over bare 16 and 18 AWG cold |
| Recovered diameter | ≈1.6mm | Grips the insulation without necking it |
| Bare wire range | 16–18 AWG | 7A for 18 AWG, 10A for 16 AWG bundled (ABYC E-11 Table XI) |
| Typical band length | 15–25mm at each break-out | Long enough to read, short enough not to stiffen the leg |
| Wall type | Single-wall polyolefin | Slits off cleanly when a circuit is re-purposed |
| Roll length | 120 ft | A trailer rebuild uses 15–25 ft, so one roll covers several vehicles |
Cut identification bands before the harness is loomed. Threading a tube onto a finished leg means cutting the loom to do it.
When to use something else
01 · The harness lives outdoors
Trailer lighting is the classic wet-location 16–18 AWG circuit, and single-wall tubing lets salt water wick down the strands. Use the 1/8" 3:1 Dual Wall on the joints and keep 2:1 for the identification bands.
02 · You are covering a splice
An insulated butt splice on 18–16 AWG measures 5–6mm across the barrel. That needs 1/4 inch; 1/8 inch is for the conductor.
03 · The band must survive fuel or solvent
Polyolefin resists most fluids but is not immune to prolonged solvent contact. Where a band sits in a fuel path, mark on a component rather than on the wire.
04 · Above 600V
Rated 600V rms. On a 1000V circuit the conductor carries its own rating and heat shrink serves as a cover over an already-rated component.
Keep reading →1/8" 3:1 Dual Wall — for wet-location joints · Automotive Wire Protection Guide · 2:1 Heat Shrink Tubing Uses
How it shrinks.
01
Measure & Select
Choose a size where the expanded diameter is 20–30% larger than your wire or bundle. Smaller tubes will slide on easier; slightly oversize is better than too tight.
02
Cut & Thread
Cut to length and thread onto the wire before making the splice. The tubing cannot pass over a crimped terminal — position it first, then complete the connection.
03
Apply Heat
The tubing starts shrinking at 100°C — use a heat gun and keep it moving until it has shrunk evenly along its length. Work from the center outward. Avoid open flame — it scorches the tubing and creates uneven shrink.
04
Inspect
Finished tubing should be tight with no bubbles or lifted edges. No adhesive will appear at the ends — this is single-wall tubing. Confirm even recovery across the full length.
Size ReferenceExpanded vs.
Expanded vs.
recovered.
Actual 1/8" tube at full expanded diameter (3.2mm) and after heat recovery. Use this as your fit reference before cutting.
Expanded: 3.2mm — slides over 16–18 AWG
Shrink ratio: 2:1 on full heat
Use it on.
01
Wire Band Marking
Band-marks conductors in control panels, distribution boards, and wiring harnesses where identification is critical and moisture is not a concern.
02
Electronics Repair
Insulates component leads, solder joints, and board-level wiring. Single-wall provides a clean, thin sleeve without added adhesive bulk.
03
Hobbyist & Maker Builds
Ideal for 3D printer wiring, robotics, LED builds, and RC applications where large roll volumes keep per-foot cost low.
04
Appliance Wiring Repair
Covers spliced leads and repaired harnesses on household appliances in dry indoor environments. UL 224 Recognized material meets installation codes.
05
Soldering Strain Relief
Provides mechanical strain relief over solder joints on wire-to-wire and wire-to-component connections in benchtop and production builds.
06
Control Panel Conductors
Organizes and insulates signal wiring, thermocouple leads, and I/O conductors inside dry rated electrical enclosures and panels.
Size Guide
1/8" 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 →Uses2:1 Heat Shrink Uses — Bundling & More
Read Guide →SizingSize Chart & Selection Guide
Read Guide →ComparisonHeat Shrink vs Electrical Tape
Read Guide →Buyer's GuideBest Heat Shrink Tubing 2026
Read Guide →Also available — 1/8" in other lines
All 13 sizes.
View line overview →3/32"2.4mm120 ft
Current1/8"3.2mm120 ft
3/16"4.8mm120 ft1/4"6.4mm120 ft5/16"8mm120 ft3/8"9.5mm120 ft1/2"12.7mm120 ft5/8"16mm90 ft3/4"19.1mm90 ft1"25.4mm90 ft1-1/4"31mm60 ft1-1/2"38mm60 ft2"50.8mm60 ftRecovered diameter is approx. 1/2 of the expanded size shown · All sizes ship to USA & Canada