Silicone Fiberglass Sleeving vs Heat Shrink

They solve different heat problems. Heat shrink seals a splice; braided sleeving shields a wire from external heat it was never meant to sit next to. Pick the wrong one and the insulation melts on first startup.

Temperature ceiling

Polyolefin heat shrink degrades above roughly 125 °C. Silicone-coated fiberglass sleeving holds 200-260 °C continuous, so it survives engine-bay radiant heat and exhaust proximity that would destroy tubing.

Install without cutting the circuit

Braided sleeving slides over an existing, energised or installed harness with no heat and no disconnect. Heat shrink needs the wire free at both ends and a gun in hand.

Reusable vs permanent

Sleeving is removable for rework and inspection. Heat shrink is one-shot - once recovered it stays.

Where each belongs

Exhaust runs, near turbochargers, radiant heat shields - use sleeving. Splice sealing, colour ID, moisture and strain relief - use heat shrink.

Dielectric note

Silicone fiberglass gives supplemental insulation around 10-15 kV/mm; the conductor must already carry its own primary insulation. It is a protective cover, not a substitute for rated wire.

Frequently asked questions