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
1-1/4"
2:1 Heat Shrink
FitsLarge bundles31mm
1-1/4 inch heat shrink tubing accommodates large multi-wire bundles, panel wiring strain relief sleeves, and cable assembly end caps in commercial and industrial electrical work. Typical applications include motor control center cable exits, large wire bundle entries at panel knockouts, and industrial conduit terminators where a 31mm initial bore is required. At 31mm expanded diameter, this tube slides freely over large wire bundles and cable assemblies and recovers to approximately 15.5mm. The 2:1 single-wall construction, qualified to UL 224, provides durable mechanical protection, abrasion resistance, and band identification on large harnesses in dry indoor environments — ideal for facility maintenance operations that need a consistent large-diameter sleeving product on hand. When the application involves outdoor exposure, wet locations, or direct moisture contact at cable penetrations, the 3:1 dual-wall with adhesive liner delivers a fully sealed sleeve that flows into gaps between mixed-diameter conductors. The 60ft roll is the appropriate stocking quantity for commercial panel projects and cable assembly work where this specialty large-diameter size is specified.
★★★★★4.7 · 225 verified ratings across the Helixal range
16 in stock · Ships in 24h
Order up to 16 online · need more? Trade pricing
Size1-1/4" · 31mm
Click any size to navigate · 60 ft per roll
$36.9960 ft spool
→ Dispatched within 24 hours — delivered in 1–3 days→ 30-day money-back guarantee — 30 days to return it
Qty
1
Secured by Stripe · No account needed
→Ships USA & Canada
→ISO 9001
→Ships 24h
SKU: B0FJH9SNZJ · 1-1/4" (31mm) · 60 ft
Spec Sheet
1-1/4"
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
1-1/4"
Expanded diameter
Metric Size
31mm
Nominal
Roll Length
60 ft
Per spool
Wire Gauge
Large bundles
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 — 1-1/4 inch, 60ft roll
Measure the bundle at its fattest point, with the lacing on.
1-1/4 inch (31mm) recovers to about 15.5mm and sleeves large multi-wire bundles and industrial cable assemblies up to roughly 25mm across. It is specified from a measurement rather than from a gauge, and that measurement is taken wrong more often than any other input on this page — because a bundle does not have one diameter, it has a range of them along its length.
How to measure something that changes size along its length
A bundle is fattest where conductors break out, where tape or lacing overlaps, and where a cable ties into it. It is thinnest on a straight run with everything dressed flat. If the tube has to travel over the fat section to reach the thin one, the fat section sets the size and the thin section decides whether the tube grips at the far end.
Take the measurement with everything that will be on the bundle already on it. A cable tie, a wrap of self-amalgamating tape or a spiral binding adds two or three millimetres per layer, and at this diameter that is the whole clearance margin. Measuring a bare bundle and dressing it afterwards is the reliable way to end up with a tube that will not pass.
Then check the low end. The recovered diameter is about 15.5mm, so anything narrower than that will not be gripped. Under a 2:1 ratio the usable span here runs from roughly 16mm to 25mm — around nine millimetres for a 31mm tube. The 3:1 version of the same nominal size opens the bottom of that range to about 10.3mm.
1-1/4 inch on the 60ft roll
| Property | Figure | Why it matters |
|---|---|---|
| Expanded diameter | 31mm (1-1/4") | Clears bundles up to about 25mm with working clearance |
| Recovered diameter | ≈15.5mm | Anything narrower than this is sleeved, not gripped |
| Usable span | ≈16–25mm | Nine millimetres wide — measure both ends of the run |
| Measure with | Tape, ties and lacing already fitted | Each layer adds 2–3mm and eats the clearance margin |
| Wall type | Single-wall polyolefin | Mechanical protection and identification in dry environments |
| Roll length | 60 ft | Multiple bundle ends and cable-tray terminations per roll |
Where a bundle changes diameter significantly along the tube, the tube follows the widest section and tents over the rest.
When 1-1/4 inch 2:1 is the wrong specification
01 · The bundle must be sealed
A 2:1 tube leaves the grooves between conductors open end to end. Use the 1-1/4" 3:1 Dual Wall, whose adhesive is pressed into those valleys until the section is solid.
02 · The bundle exceeds about 25mm
Step to 1-1/2 inch, which clears roughly 30mm. Working a tube on by hand at this size guarantees uneven seating.
03 · The run tapers a long way
If one end is 24mm and the other 14mm, no single 2:1 tube covers both. Either use two pieces or move to the 3:1 ratio.
04 · Rated barrier penetrations
A fire- or pressure-rated bulkhead needs a listed transit system. Heat shrink is not a substitute for a rated barrier assembly.
Keep reading →1-1/4" 3:1 Dual Wall — for sealed bundles · What Size Heat Shrink Tubing · Heat Shrink Size Calculator
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.
Watch
All Videos →See 1-1/4" In Use
Size ReferenceExpanded vs.
Expanded vs.
recovered.
Actual 1-1/4" tube at full expanded diameter (31mm) and after heat recovery. Use this as your fit reference before cutting.
Expanded: 31mm — slides over Large bundles
Shrink ratio: 2:1 on full heat
Use it on.
01
Large Cable Bundle Management
Consolidates and protects the largest cable bundles in industrial facilities, data centers, and power distribution environments.
02
Harness Band Marking
Provides large-diameter band identification on industrial wire harnesses for maintenance, commissioning, and future troubleshooting.
03
Pipe & Hose Identification
Identifies pipes, hoses, and conduits in process plants, mining operations, and heavy manufacturing facilities.
04
Panel Entry Strain Relief
Applied at the point where large cable bundles enter panels and enclosures to distribute mechanical stress and prevent jacket wear.
05
Cable Tray Finishing
Provides a clean finished end cap on cable tray bundles at termination points in industrial and commercial electrical installations.
06
Industrial Mechanical Protection
Covers large cable assemblies in environments where abrasion, oil, and mechanical contact are present but submersion is not.
Size Guide
1-1/4" 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 →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 — 1-1/4" in other lines
All 13 sizes.
View line overview →3/32"2.4mm120 ft1/8"3.2mm120 ft3/16"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 ft
Current1-1/4"31mm60 ft
1-1/2"38mm60 ft2"50.8mm60 ftRecovered diameter is approx. 1/2 of the expanded size shown · All sizes ship to USA & Canada