Here are some of the mechanical features of aluminum profiles for windows and doors;

4. Adjust the Rollers Most sliding doors have screws located at the bottom of the door, often accessed through small holes. Use the appropriate screwdriver to turn these screws. Turning the screws clockwise typically raises the door, while counterclockwise lowers it. Make small adjustments and test the door after each adjustment until it glides smoothly along the track.

Columns are the round or square pillars, posts or poles that flank an entranceway, and a cover flange or escutcheon is a piece of metal that is used for decoration or protection. These are typically found around the base of a post or at a point where the rail ends against a solid wall.
The decorative pieces that sit atop a post on a wrought iron fence in order to cover it are called post caps. These keep debris and water from building up inside the post, and they come in a range of designs from ball style caps to less ornate ‘flat’ or ‘standard’ post caps.