ASTM A254 BHG2 Bundy Tube Instrumentation Tube Copper-Brazed Steel Tubing

ASTM A254 Copper-Brazed Steel Tubing BHG2 Bundy Tube

A Bundy tube is not just any steel tube; it's defined by its unique manufacturing process, which gives it exceptional properties. Its unique double-wall, copper-brazed construction gives it an unparalleled combination of strength, fatigue resistance, and leak-proof integrity, making it the undisputed first choice for the most critical hydraulic and fuel lines in vehicles.

1. Strip Preparation: A low-carbon steel strip (typically ASTM A254 Grade 2) is first coated with a layer of copper.

2. Double Rolling: This copper-coated strip is then passed through a series of rolls that form it into a seamless-looking, double-walled tube. The strip is rolled twice around its own longitudinal axis, creating a tight, overlapping seam.

3. Copper Brazing: The tube is then passed through a continuous furnace with a controlled atmosphere (a hydrogen-nitrogen mix). The heat melts the copper coating at the seam, which acts as a brazing filler metal. Capillary action draws the molten copper into the entire length of the seam, creating a strong, uniform, and leak-proof metallurgical bond.

4. Sizing and Cutting: The brazed tube is then cooled, drawn through dies to achieve precise final dimensions (OD, wall thickness), and cut to length.

Dimensional Accuracy

*Custom Sizes: We are capable of fabricating Bundy tube sizes which are not regularly used. By combining one or more processes of cold draw and annealing, Bundy tubes can be made to many other sizes to meet demands for special applications.

General Size and Tolerance

Comparison with Alternative Tubing

Applications

1. Automotive & Transportation (Largest Application)

2. Refrigeration & Air Conditioning

3. Heat Exchangers

4. Aerospace & Aviation

5. Industrial Applications

6. Hydraulic Control Systems

7. Instrumentation Tubing