Red 12 mm heat-shrink tubing per meter

Red heat-shrink tubing without adhesive, Ø 12 mm before shrinking and Ø 4 mm after free shrinking, 3:1 shrink ratio, sold per meter.

Single wall: implications

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

Polarity marking

Red is used to mark the positive on a DC installation. The color code is only valid if consistently applied throughout the vessel: a red sleeve on a negative is worse than no sleeve at all.

Choosing the correct diameter

The Ø 12 mm must fit over the widest point to be covered, and the Ø 4 mm 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
• Internal diameter before shrinking: 12 mm
• Internal diameter after free shrinking: 4 mm
• No adhesive — mechanical grip, no sealing
• Color: red
• Sold per meter — 1 quantity = 1 meter
• Delivered in continuous lengths up to 1.2 m maximum (procurement length)

What this datasheet does not cover

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).