Copper is a ductile metal with very high thermal and electrical conductivity. Pure copper is rather soft and malleable. However, adding various metal alloys changes the properties of copper which makes it useful in many applications. HRS35 copper is an alloy that is 99.5% pure copper with a .5% mixture of other elements. These other elements include small amounts of tin (Sn), cobalt (Co), zinc (Zn), nickel (Ni), and phosphorous (P). The mixture of these elements produces a stronger copper alloy that has increased durability and resistance to heat fatigue and out-performs standard copper while still maintaining its advantages.
Takagi Industrial Company USA, Inc. teamed up with a copper manufacturing company and spent countless hours researching the benefits of this alloy and found that it is much stronger and harder than the standard C1220, which is the copper used in most other heat exchangers. HRS35 has 8 times the tensile strength of standard copper. However, even at high temperatures, HRS35 maintains a fine grain and high strength and is resistant to the damaging effects of erosion and stress fractures.