Pins are critical to building with the Technic system, as they
keep bricks and beams together. A pin is a small connector
that enters pin holes or axle holes to connect two or more
adjacent pieces. As you can see in Figure 2-6, pins vary in
length and shape, as well as degree of friction. While simple,
pins are indispensable for holding Technic constructions
together. The largest Technic sets can include several hundred pins. They’re really that important!
Like axles, pins can be used in either pin or axle holes.
Unlike axles, each pin has a collar that makes it impossible
to push it completely through a hole. For example, the most
basic pin is 2 studs long, and each of its ends can be pushed
1 stud deep into a hole but no farther. The long pin, which
is 3 studs long, has one end that can be pushed 1 stud deep
and another that can be pushed 2 studs deep. The collars
on pins keep bricks together, and pin holes are shaped to
accommodate them (see Figure 2-7).
Some pins come in two variants: one that can rotate
freely inside a pin hole and another that requires some force.
The latter type is called a pin with friction or a friction pin.
Different types of pins come in different colors.
You should be able to identify pins with friction by their
ridged appearance and behavior, no matter what color they
are. Figure 2-8 shows a range of the most common pins in a
variety of colors.