1)aluminium weld on hinge mainly made of aluminium,the pin is made of stainless steel 2)this hinge has size 40mm to 260mm

Aluminium weld on hinge.

This kinds of  car  hinge are mainly made of Aluminums.

There is a bearing or a washer in the middle,which made of stainless steel.

And it has a fixed pin inside,which is made of stainless steel .

On  the top ,It can be attached with a grease.