Shop our platinum and platinum-iridium marker band inventory online at
View AS9100 Cert | View ISO 13485:2019 (Limited Scope) Cert

CDA 521

CDA 521 Technical Data


CDA 521 is a copper-tin filler metal used for brazing ferrous alloys, such as steel. This alloy is typically used in furnace brazing of steels where use of pure copper is no permissible. 

Brazing Characteristics

CDA 521 has good wetting characteristics on ferrous based materials, particular steel in furnace brazing applications. Maximum strength and joint integrity are obtained where joint clearance falls within the range of 0.003in. – 0.005in. per side.

Properties of Brazed Joints

The properties of a brazed joint are dependent upon numerous factors including base metal properties, joint design, metallurgical interaction between the base metal and the filler metal. 


CDA 521 alloy conforms to: Unified Numbering System (UNS) C52100

Available Forms

Wire, strip, engineered preforms, specialty preforms per customer specification, powder and paste. 

Compare With

  • AWS: RCuSn-C
  • Lucas: CDA 521
  • PI: CDA 521
  • UNS: C52100


  • Brazing Temperature Range High: 1980 F / 1082 C
  • Brazing Temperature Range Low: 1930 F / 1054 C
  • Liquidus: 1880 F / 1027 C
  • Solidus: 1620 F / 882 C



  • Cu: 92%
  • Sn: 7.7%
  • P: 0.35%

The information and recommendations contained in this publication have been provided without charge & compiled from sources believed to be reliable and to represent the best information available on the subject at the time of issue. No warranty, guarantee, or representation is made by the Prince and Izant Company, Inc. as to the absolute correctness or sufficiency of any representation contained in this and other publications; Prince and Izant Company, Inc. assumes no responsibility in connection therewith; nor can it be assumed that all acceptable safety measures are contained in this and other publications, or that other or additional measures may not be required under particular or exceptional conditions or circumstances. The company and product names referenced herein are for identification purposes only. All trademarks and registered trademarks are the property of their respective owners.

Request a Quote Now!