Top plate: Usually 2x4.

Sole plate: Usually 2x4.

Studs: Usually 2x4.

Header: Size is determined by length. Usually 4" and 1" thickness per 12" of length.

Trimmer: Supports the header. Usually 2x4.

Sill plate: Stud underneath the window. Usually 2x4.

Cripple: Supports the sill plate.

新建的房子很多都用2 x 6 Stud, 这样可以用较厚的保温材料。