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RWMA / AWS Standards Est. 1998 | Monterrey, N.L.
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RWMA CLASS 3

Copper Class 3 – Copper Cobalt Beryllium (C17500)

High hardness + balanced conductivity. For AHSS steels, coated materials and high-volume production. Specifications per AWS J1.3.

Technical Specifications

Conductivity
≥45% IACS
Hardness
≥90 HRB
Temperature
525°C
Standard
AWS J1.3

Properties Table (AWS J1.3)

Property Value Unit
RWMA Class Class 3 -
UNS Code C17500 -
Composition Cu + 2.4-2.7% Co + 0.4-0.7% Be % wt
Electrical Conductivity ≥45 % IACS
Hardness ≥90 HRB
Thermal Conductivity 188 W/m·K
Softening Temperature 525 °C
Density 8.26 g/cm³

When to Use C17500 (CuCoBe)

C17500 (Copper Cobalt Beryllium) is the choice when you need higher hardness than Class 2 with balanced conductivity:

  • Superior hardness (≥90 HRB) vs Class 2 (≥75 HRB) for extended electrode life
  • Mushrooming resistance in high-volume production
  • Better AHSS performance (advanced high-strength steels)
  • Higher softening temperature (525°C) than Class 2
  • Intermediate beryllium content (0.4-0.7% Be) safer than Class 4

Comparison: C17500 vs C17510

Characteristic C17500 (CuCoBe) C17510 (CuNiBe)
Main Element 2.4-2.7% Cobalt 1.4-2.2% Nickel
Beryllium Content 0.4-0.7% Be 0.2-0.6% Be
Conductivity ≥45% IACS ≥45% IACS
Hardness ≥90 HRB (typical 96-100) ≥90 HRB (typical 96-102)
Primary Use Coated steels, AHSS Nut projection, AHSS
Relative Cost Similar Similar

Main Applications

AHSS/UHSS Steels

Advanced and ultra-high strength steels generating more heat and pressure

Coated Materials

Steels with coatings requiring higher electrode hardness

High Production

Lines with >20 welds/minute where electrode life is critical

Seam Welding

Wheels for continuous seam welding on fuel tanks

Safe Handling Note: Beryllium alloys in solid bar or plate form are completely safe to handle. Potential risk exists only during machining if dusts are generated. Download the OSHA 1910.1024 Safe Handling Guide