Method for making heat pipes

A method of expanding a tube and forming a groove in said tube, said method comprising:

• providing a tube expanding and groove forming tool with
• a drive shaft,
• a tool head having a first end attached to said drive shaft, a second end, and an expander tool a widest portion of which is located between said first and second ends, and
• a groove forming tool mounted on said tool head between said widest portion of said expander tool and said second end;
• inserting said tool head into said tube, thereby expanding said tube;
• then
• withdrawing said tool head from said tube;
• and
• forming a groove in said tube only during said withdrawing step.

A method of expanding a tube and forming a groove in said tube comprising:

• providing a tube expanding and groove forming tool with
• a drive shaft having a longitudinal axis,
• a tool head attached to said drive shaft, said tool head having an expander tool, and
• a rolling element mounted on a shaft, said shaft being slidably mounted in an inclined groove formed in said tube expanding and groove forming tool and being rotatable with respect to said tool head about an axis of rotation which is at least generally perpendicular to said longitudinal axis of said drive shaft;
• inserting said tool head into said tube, thereby expanding said tube and causing said rolling element to retract within said slot so as not to forge a groove in said tube;
• and
• withdrawing said tool head from said tube, thereby causing said rolling element to extend within said slot into pressurized rolling engagement with said tube and forging said groove in said tube without cutting.