High Quality Automotive Hydraulic Steel Brake Line Tubes

Zinc Plated Bundy Tubes

Zinc Plated Bundy Tubes

The steel brake line tubes are used as a common automotive tubing for hydraulic brake, fuel, transmission cooling, and power steering lines.

The basic tubes are copper brazed steel tubes, made to general automotive standard specifications like SAE J527, ASTM A254. They are further treated by zinc plating (galvanizing), GALFAN coating, PVF coating, aluminum-rich epoxy coating, and nylon coating for enhanced protection against corrosion.

The final tubes meet major industrial standards like JASO M101, GM123M/124M etc., and the are strictly tested because they must be in good condition to ensure the safety driving of vehicles on and off road.

Online Monitoring

When tube is formed and brazed in the continuous production line, instant Eddy current automatic inspection system keeps detecting any potential imperfections of inner structure of the tube. Once the imperfections are detected, they will be automatically shown and notified by the system:

  1. An alarm sound is triggered and broadcast by a loud speaker.
  2. A flashing alert light on the machine shall be turned on.
  3. An automatic online printer shall mark the tube sections with imperfections with ink, then the imperfect tube sections shall be cut and removed.

Mechanical Performance Tests

The following tests shall be done to make sure the brake line tubes are qualified for hydraulic applications of automobiles.

  1. Tensile test.
  2. Hardness test.
  3. Bending test.
  4. Expansion test.
  5. Developing test.
  6. Flattening and bending test.
  7. Pressure-proof test.
  8. Burst pressure test.
Surface Coating Tests

The following tests shall be conducted to determine how the surface coating/plating performs when protecting the brake line tubes from corrosion.

  1. Coating/plating thickness test.
  2. Corrosion resistance test (neutral salt spray, i.e. NSS).
  3. Film performance test (varies according to coating/plating types).