2.5 sq mm Fiberglass Insulated High-Temperature Wire

2.5 sq mm (≈ 14 AWG) fiberglass wire is mainly used for heating-element leads and small furnace power connections. RCI braids silicone-varnished E-glass yarn over a flexible stranded conductor, giving a wire that keeps its insulation at temperatures where PVC and rubber would melt or crack. The standard rating is 250°C continuous, with higher-temperature constructions available on request.

For 2.5 sq mm we build the conductor from 50 strands of 0.25 mm wire or 20 strands of 0.40 mm wire. The finer 0.25 mm stranding is more flexible and easier to route around heater terminals; the 0.40 mm option is stiffer but more robust where the wire is clamped or vibrates. Maximum conductor resistance is about 7.98 Ω/km at 20°C for bare copper (IEC 60228 Class 5 reference), and the copper weight is roughly 2.27 kg per 100 m before insulation.

You can choose bare copper, tin-plated copper, nickel-plated copper (NPC), SS + copper or pure nickel conductors. NPC and pure nickel resist oxidation at the higher end of the temperature range, while SS + copper adds strength. Insulation can be single or double fiberglass braid, and an outer stainless-steel braid can be added for abrasion protection in steel plants and foundries.

As a rough guide, 2.5 sq mm fiberglass wire carries around 20 A in free air. The real limit depends on ambient temperature, bundling and how the wire is installed, so treat this as an estimate and share your load and ambient with us for confirmation.

Choosing the right size: If your load is lighter, the next smaller size is 1.5 sq mm Fiberglass Wire, which is easier to bend and terminate. This is the largest standard size we list; larger sizes and multicore versions can be made to order. Under-sizing a high-temperature wire makes it run hotter, which shortens insulation life, so it is better to choose by current and ambient temperature together.

2.5 sq mm Fiberglass fiberglass wire is supplied on coils or drums in standard and cut lengths, in natural, white, red, black, yellow, blue and other braid colours. For a quote, tell us the conductor material, single or double braid, whether you need an SS braid, the total length and the maximum operating temperature.

Every batch is made at our Rewari factory and ships with a Material Test Certificate. Use the fiberglass configurator to choose conductor, braid and length and download a watermarked technical data sheet, or ask for a quote on WhatsApp.