Composite dual tubing.

摘要

The present invention relates to a steel tubing and more particularly a composite dual tubing which can be suitably used for an axhaust pipe capable of effectively reducing the radiated noise from the exhaust pipe of automobiles.
<??>Several known dual tubings are effective occasionally for the reduction of radiated noise, but their effects are drastically reduced at high temperature. A metallic dual tubing of the present invention comprises: lugs (20a); lugs (20a) and heat-resistant filer matarial (24); or, the spacer member (16) and the heat-resistant filler member (17).