Composite weldable stud and method of using same

A friction-weldable stud comprising a first body made of a first material having an elongate shank, a collar extending outwardly from said shank near one end thereof, said collar having a first surface facing toward the other end of said shank, said first surface having generally radially-extending grooves extending substantially from said shank to the periphery of said collar for engagement by a cooperating surface of a welding tool chuck, whereby axial and rotational forces can be applied to the stud through the chuck, said collar having a second surface facing away from said other end of said shank and being annular, and a second body made of a second material which is different than said first material, said second body having a weldable nose extending from said collar in a direction away from said shank, said nose having an axis which is substantially coaxial with an axis of said shank, and said second body and said first body having cooperating means for affixing said second body to said first body, whereby said first body and said second body can rotate and move axially together.

A composite weldable stud for welding a first plate of predetermined thickness to a second plate, said stud comprising a first body of one material having a shank and a collar extending outwardly from said shank near one end thereof, a second body of a different material having a weldable nose extending from said first body in a direction away from said shank, said nose having an axis which is substantially coaxial with an axis of said shank, said nose having a length which is longer than the thickness of the first plate, and said second body and said first body having cooperating means for affixing said second body to said first body, whereby said first body and said second body can move together as a unit.

A method of affixing a first metal plate to a second metal plate made of a dissimilar method, said metal comprising providing a composite stud having a first body made of a metal compatible with said first plate, with said body having a collar extending outwardly of a predetermined diameter, said stud further having a second body of a metal compatible with said second plate, said second body comprising a generally cylindrical, friction-weldable nose extending outwardly from said collar substantially coaxially with an axis of said first body, said second body being affixed to said first body;

• forming a hole in said first plate of a diameter greater than the diameter of said nose and smaller than the diameter of said collar;
• placing said nose through said hole and into contact with said second plate;
• and welding said nose to said second plate and said collar to said first plate.

A method of affixing a first plate of one material to a second plate of a different material, said method comprising providing a composite stud having a first body made of a material which is compatible with said first plate, said body having a collar, said stud further having a second body made of a material which is compatible with said second plate, said second body having a weldable nose extending beyond said first body away from said collar, said second body being affixed to said first body, said nose having a length exceeding the thickness of said first plate;

• forming a hole in said first plate of a size which is larger than the cross section of said nose and smaller than said collar;
• placing said nose through said hole and into contact with said second plate;
• and welding said nose to said second plate and said collar to said first plate.