The Move toCopper-Nickel Tubing 

Copper had been provedsince the early days to have many good attributes. It was easy to bend and hadvery high corrosion resistance, but there was concern about its lowcorrosion-fatigue strength. When copper-nickel was introduced, it displayedcorrosion resistance similar to copper, higher general strength and betterfatigue strength. Good formability allows ease of flaring and bending, andalthough the metal cost is greater than that of steel alternatives,copper-nickel is very attractive in view of its extra life, trouble-freeinstallation and safety/reliability characteristics. 

Properties ofCopper-Nickel Brake Tubing

The copper-nickelalloy used for brake tubing typically contains 10% nickel, with iron andmanganese additions of 1.4% and 0.8% respectively. The product conforms to ASTMB466 (American Society for Testing and Materials), which specifies dimensions,tensile strength and yield strength. Formability and internal cleanlinessconform to specifications SAE J527, ASTM A254 and SMMT C5B (Society of Motor Manufacturersand Traders). Also, the alloy meets the requirements for pressure containment,fabrication and corrosion resistance for ISO 4038 (International StandardsOrganization) and SAE J1047.

The mechanicalproperties of alloy C70600 in comparison with steel and copper are shown inspecification.

Alloy C70600 isnormally supplied as redrawn tubing in the annealed condition. The combinationof strength and good ductility give excellent formability. 

As copper-nickel issofter than steel, it was first feared that fretting might be a problem.Experience has shown this is not the case.

Corrosion Resistance

For many years priorto its application as a brake tubing material, alloy C70600 had been used inships, power station condensers and hydraulic lines on tankers, and haddisplayed excellent resistance to saline conditions. Early tests revealed thatcopper-nickel has almost the same resistance to burst pressure as steel. Intesting, however, when exposed to salt spray over 180 days, steel''s burststrength decreases significantly. The copper alloy remains consistentlyresistant.

For tubes covered witha moist, salty mudpack for six months, brazed steel was severely corrodedresulting in perforation of the tubing wall; whereas, only superficial generalcorrosion was found on the copper-nickel tubing. ISO 4038 and SAE J1047 includea corrosion resistance requirement referring to ISO 3768 asking for a minimumburst pressure of 110 MPa after 96 hours in neutral salt spray. Swedishrequirements include a resistance at least equal to 25µ of zinc. In all casesalloy C70600 easily exceeds the required corrosion resistance.

Copper-nickel braketubing provides superior reliability and assures both manufacturers and vehicleowners improved durability for effective long-life functioning of the brakesystem.

The Move toCopper-Nickel Tubing 

Copper had been provedsince the early days to have many good attributes. It was easy to bend and hadvery high corrosion resistance, but there was concern about its lowcorrosion-fatigue strength. When copper-nickel was introduced, it displayedcorrosion resistance similar to copper, higher general strength and betterfatigue strength. Good formability allows ease of flaring and bending, andalthough the metal cost is greater than that of steel alternatives,copper-nickel is very attractive in view of its extra life, trouble-freeinstallation and safety/reliability characteristics. 

Properties ofCopper-Nickel Brake Tubing

The copper-nickelalloy used for brake tubing typically contains 10% nickel, with iron andmanganese additions of 1.4% and 0.8% respectively. The product conforms to ASTMB466 (American Society for Testing and Materials), which specifies dimensions,tensile strength and yield strength. Formability and internal cleanlinessconform to specifications SAE J527, ASTM A254 and SMMT C5B (Society of Motor Manufacturersand Traders). Also, the alloy meets the requirements for pressure containment,fabrication and corrosion resistance for ISO 4038 (International StandardsOrganization) and SAE J1047.

The mechanicalproperties of alloy C70600 in comparison with steel and copper are shown inspecification.

Alloy C70600 isnormally supplied as redrawn tubing in the annealed condition. The combinationof strength and good ductility give excellent formability. 

As copper-nickel issofter than steel, it was first feared that fretting might be a problem.Experience has shown this is not the case.

Corrosion Resistance

For many years priorto its application as a brake tubing material, alloy C70600 had been used inships, power station condensers and hydraulic lines on tankers, and haddisplayed excellent resistance to saline conditions. Early tests revealed thatcopper-nickel has almost the same resistance to burst pressure as steel. Intesting, however, when exposed to salt spray over 180 days, steel''s burststrength decreases significantly. The copper alloy remains consistentlyresistant.

For tubes covered witha moist, salty mudpack for six months, brazed steel was severely corrodedresulting in perforation of the tubing wall; whereas, only superficial generalcorrosion was found on the copper-nickel tubing. ISO 4038 and SAE J1047 includea corrosion resistance requirement referring to ISO 3768 asking for a minimumburst pressure of 110 MPa after 96 hours in neutral salt spray. Swedishrequirements include a resistance at least equal to 25µ of zinc. In all casesalloy C70600 easily exceeds the required corrosion resistance.

Copper-nickel braketubing provides superior reliability and assures both manufacturers and vehicleowners improved durability for effective long-life functioning of the brakesystem.