Machine Graded Pine is found all throughout modern timber framing. Walls are usually framed almost completely out of MPG pine, which includes the studs, bottom plates, and top plates.
In Australia, radiata pine is commonly graded this way, and for wall framing, the timber is sawn into sizes with rectangular cross section dimensions such as 90×35 mm, 90×45 mm, 70×35 mm, and 70x45mm. Other sizes are also readily available.
The machine grading process involves feeding the timber member through rollers which bend the timber and measure its stiffness. From the stiffness, other properties such as strength and stress capacity are inferred. For a more detailed explanation visit the Wood Solutions page on Machine Stress-Grading.