I see that there are at least three different types of axles that can be used with LEGO wheels. I can name the first two — Technic axle and Technic pin — but I cannot name the third, which is like a Technic pin, but smaller.
Note that I've only seen it integrated into a larger part, such as a brick or plate, as shown in the image. I see that BrinkLink sometimes refers to parts like this as having "wheels holder" pins, but that seems to be a term that could apply to the first two types of axles as well.
Does a common and more precise name exist for this type of pin?