SPECIFICATION: Thread Type: Metric; Thread Size: M3 x 20mm; Material: Carbon Steel; Finish: Carburization + Black Zinc Plated APPLICATION: Mainly used in notebook , 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 slow locked during the initial introduction to avoid thread slippage. ADVANTAGES: It is made of high quality carbon steel with enough strength and proper toughness after carburizing and black zinc plating. The screw is corrosion resistant and durable.