This is an official LEGO® part. LEGO Part Technic Pin – Black, with Short Ridges
A LEGO Technic pin is a small, cylindrical plastic piece used in LEGO Technic sets to connect different elements together. This one is round on both end. However it can also have a cross-shaped hole. LEGO Technic pins come in a variety of lengths and styles. They are an essential component in building complex Technic models with moving parts and mechanisms. Often used to create support structures, hinges, joints, and other types of articulation in LEGO Technic models.
The different kinds of LEGO Technic pins vary in length, shape, and function. This allows for different types of connections and movement in a LEGO Technic model. Some pins have friction or locking mechanisms. Other can be use to hold parts in place. Finally others may have ball joints or axles that allow for rotation and movement.
Different pins have varying levels of strength or durability, depending on the demands of the model. Ultimately, the choice of which Technic pin to use depends on the specific needs of the build and the desired outcome.
Lego Part Number: 2780
All my parts are sourced from either new sets or reputable sources.