3 mm heat-shrink tubing red per meter

Red heat-shrink tubing non-adhesive, 3 mm diameter before shrinking and 1 mm after free shrinking, 3:1 shrink ratio, sold per meter.

Single wall: implications

Non-adhesive tubing grips the support mechanically without sealing it. This is suitable for polarity marking and circuit identification. For a junction that must remain watertight — crimped ferrule exposed, wet bulkhead penetration — use adhesive-lined tubing: the adhesive version exists in the same diameter.

Polarity marking

Red marks the positive on a DC installation. The color code only has value if applied consistently throughout the installation: a red sleeve on a negative is worse than no sleeve at all.

Choosing the correct diameter

The 3 mm diameter must fit over the largest point to be covered, and the 1 mm diameter after shrinking must be smaller than the support so the tubing grips. Between these two values, the 3:1 ratio provides a comfortable adjustment range.

Specifications

• Shrink ratio: 3:1
• Inner diameter before shrinking: 3 mm
• Inner diameter after free shrinking: 1 mm
• Non-adhesive — mechanical grip, no sealing
• Color: red
• Sold per meter — 1 quantity = 1 meter
• Delivery in continuous lengths up to 1.2 m maximum (supply length)

What this datasheet does not state

Hardware reference without published manufacturer datasheet: the shrink ratio and diameters above come from the supplier catalog, but we have no certified temperature range, UL approval, or reference standard for this line. For applications where these guarantees matter — specified watertightness, engine harness, contractual use — use the TE Connectivity ATUM range from the catalog, documented (UL E85381, AMS-DTL-23053/4, −55 °C to +110 °C).