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CO25 Filler Welding Wire – Composition, Properties, and Uses

CO25 Filler Wire

Choosing the right filler wire is crucial for welding strong and durable welds. CO25 filler wire is popular among welders, especially in the automotive and aerospace industries. But what is CO25 filler wire, and why is it so widely used? In this blog post, we’ll explore everything you need to know about CO25 filler wire, from its composition and mechanical properties to its uses and corrosion resistance.

What is CO25 Filler Welding Wire?

CO25 filler wire is a type of hard-facing welding material. It comprises tungsten, nickel, and chromium alloys commonly used for high abrasion and impact resistance applications. It has excellent arc stability and higher metal deposition rates than other alloys. The CO25 filler wire helps improve wear resistance in industrial components like gears, shafts, press rolls, rock crushers etc. Due to its excellent thermal properties, this filler wire type is ideal for use on parts with high mechanical stress at elevated temperatures. Additionally, it helps increase the life expectancy of your parts by providing superior wear protection from harsh working environments.

CO25 Filler Coated Wire Composition

CO25 filler wire is a welding wire made from nickel, chromium, and iron. The composition of CO25 filler wire results in a high strength-to-weight ratio and excellent corrosion resistance. It also contains small amounts of other elements that further enhance its properties, such as manganese, molybdenum, and silicon.

Co Cr W C Ni Mo Others Hardness Density Melting Range
Bal. 20 15 0.1 10 < 1.0 Fe, Si, Mn 20 – 45 HRC 8.31 g/cm3 1329 – 1410 ºC

CO25 Filler Welding Wire Mechanical Properties

CO25 filler welding electrode boasts high tensile strength, making it ideal for welding high-stress areas. It also has exceptional toughness, allowing it to resist cracking even under extreme conditions. CO25 filler wire produces strong and ductile welds with excellent corrosion resistance.

CO25 Filler Welding Wire Physical Properties

CO25 filler welding alloy has a melting point of around 1400°C (2550°F) and a density of 8.9 g/cm3. It has a low coefficient of thermal expansion, making it ideal for welding materials with different coefficients. CO25 filler wire also has good electrical conductivity, essential for welding applications requiring precise heat input control.

CO25 Filler Coated Wire Trade Name

Class Stellite
CO25 Stellite®25

CO25 Filler Welding Wire Uses

CO25 filler wire is widely used in the aerospace and automotive industries due to its high strength-to-weight ratio and corrosion resistance. It is commonly used for welding high-stress areas such as jet engines, aircraft frames, and racing cars. CO25 filler wire is also suitable for welding stainless steel, nickel alloys, and other high-performance materials.

CO25 Filler Coated Wire Corrosion Resistance

CO25 filler metal is renowned for its excellent corrosion resistance, making it ideal for harsh environments. Its corrosion resistance is due to chromium, which forms a protective oxide layer on the surface of the weld, preventing rust and corrosion. This makes CO25 filler wire an excellent choice for welding in applications where the weld will be exposed to corrosive environments.

CO25 Filler Welding Wire Heat Treatment

CO25 filler wire can be heat treated to improve its mechanical properties. This involves heating the weld to a specific temperature and cooling it slowly. Heat treatment can increase the weld’s strength, toughness, and flexibility, making it more resistant to cracking and deformation.


In summary, CO25 filler wire is a powerful welding wire with excellent mechanical and physical properties. Its high strength-to-weight ratio, corrosion resistance, and suitability for high-performance materials make it a popular choice among welders in the aerospace and automotive industries. If you’re considering using CO25 filler wire in your next welding project, choose a reputable supplier and consult a welding expert to ensure you achieve the best results possible.

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