8412.31.00 - Linear acting (cylinders)

This category encompasses pneumatic power engines and motors specifically designed for linear motion. These devices, commonly referred to as pneumatic cylinders, utilize compressed air to generate a straight-line force and displacement. They are integral components in automation and machinery, performing tasks such as pushing, pulling, clamping, and lifting. The key characteristic is their rectilinear operation, distinguishing them from rotary pneumatic motors.

Within the broader group of "Pneumatic power engines and motors," this heading specifically targets linear actuators. Its sibling category, 8412.39.00, covers "Other" pneumatic power engines and motors that do not operate in a linear fashion, which would typically include rotary pneumatic motors. Therefore, classification into 8412.31.00 is determined by the fundamental mode of operation – linear versus rotary.

The subcategories within 8412.31.00 further refine the classification of linear pneumatic actuators based on their construction. "Tie-rod type" cylinders (8412.31.00.40) are characterized by external tie rods that hold the cylinder end caps together. "Other" linear cylinders (8412.31.00.80) would encompass a range of other construction types, such as internally threaded, tie-tube, or integral construction, where the distinction from tie-rod type is based on the method of securing the cylinder components.