Specification: Thread Type: Metric; Thread Size: M4 x 8mm; Material: Carbon Steel; Finish: Carburization + Black Zinc Plated Application: Mainly used in notebooks, computer monitors, fans and other 3C equipment products. How to use: It is driven by a cross groove, with uniform force, easy to lock, not easy to slip, and convenient and quick to use. Notice: Regardless of manual or electric locking, it must be guided and slowly locked to avoid thread slippage. Advantage: It is made of carbon steel with enough strength and proper toughness after carburizing and black zinc plating. The screw is corrosion resistant and durable.