Double Walled Steel Tubing is a steel tube for pressure piping, which is manufactured from electrolytic copper coated steel strip (both surfaces). The strip is wound into continuous tubular with double-layered wall and then copper brazed in a special furnace using the coated copper as filler metal.

The tube possesses higher withstanding pressure and higher vibration fatigue strength. Furthermore, the tube is also equipped with superior properties such as solderability, brazeability, bendability, and workability in end terminal preparation. As a pressure tubing material with extensive reliability and good processing characteristics, this tube is used for several purposes, such as brake tubing, power steering on vehicles, and many more.

Standard dimension, tolerance, and withstand pressure (Conforming to JASO M101-94)

Nominal diameter	Outer diameter (mm)		Wall thickness (mm)		Guarantee pressure (MPa)	Burst pressure (MPa)
	Standard dimension	Tolerance	Standard dimension	Tolerance
4	4	±0.08	0.7	±0.08	34.3	108
4.76	4.76	±0.08	0.7	±0.08	34.3	108
6.35	6.35	±0.08	0.7	±0.08	34.3	83.3
8	8	±0.1	0.7	±0.1	24.5	66.2
10	10	±0.1	0.7	±0.1	24.5	53.9

• Please feel free to consult USUI for the availability of tube sizes other than listed above.
• Tubes will be applied with various treatments and/or finishings on external surfaces per intended use.
  • Surface Treatment