Marine adhesive-lined heat-shrink tubing insulates and seals properly prepared electrical connections. Unlike an ordinary loose sleeve, the inner adhesive activates with heat to help protect the joint from moisture and provide strain relief. Ancor offers several starting diameters and colours; choosing the right size requires measuring the cable and the widest terminal first.

Start with the unshrunk opening

1/2-inch series

Nominal 12.7 mm starting diameter; the manufacturer lists recovery to approximately 4 mm.

3/4-inch series

Nominal 19 mm starting diameter; recovers to approximately 6.4 mm.

1-inch series

Nominal 25.4 mm starting diameter; recovers to approximately 7.9 mm.

These are 3:1 adhesive-lined products: the tubing shrinks to roughly one-third of its initial diameter. The stated size is the unshrunk diameter, not the final recovered diameter.

Ancor adhesive-lined heat-shrink tubing chart

This 48-inch selection comes in black, red and yellow versions. The manufacturer’s AWG ranges are guidelines; the widest lug or splice outside diameter also determines which tubing will fit.

MPN Starting diameter Recovered diameter Colour Pack length Manufacturer wire range
305148 1/2 in 5/32 in Black 1 × 48 in 8–4 AWG reference
305648 1/2 in 5/32 in Red 1 × 48 in 8–4 AWG reference
306148 3/4 in 1/4 in Black 1 × 48 in 8–2/0 AWG reference
306648 3/4 in 1/4 in Red 1 × 48 in 8–2/0 AWG reference
306948 3/4 in 1/4 in Yellow 1 × 48 in 8–2/0 AWG reference
307148 1 in 5/16 in Black 1 × 48 in 2–4/0 AWG reference
307648 1 in 5/16 in Red 1 × 48 in 2–4/0 AWG reference
307948 1 in 5/16 in Yellow 1 × 48 in 2–4/0 AWG reference

Manufacturer specifications: cross-linked polyolefin, adhesive lining, 3:1 shrink ratio, activation at 125°C (257°F), operating range −40°C to 110°C.

Fitting and recovering adhesive-lined tubing

Measure both the cable insulation and the widest point of the crimp or lug. Select tubing that slides over the joint before heating but recovers firmly onto the cable, with enough length to cover the exposed connection and overlap intact insulation.

A wire-gauge recommendation is not a finished outside-diameter measurement

A cable termination may be wider than its wire insulation. Check the actual assembly and follow the manufacturer’s heat-tool instructions, applying heat evenly without damaging the cable or adjacent components.

Ancor heat-shrink tubing by diameter and colour

Open the matching product for its current details and availability.

More marine electrical parts guides

Ancor heat-shrink butt connectors · Marine battery cable assemblies

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