Needle mounting system and a method for mounting a needle assembly

A method for mounting a needle assembly to a needle mount of an injection device, the method comprising:

• i) inserting the needle mount into an interior hub of a needle assembly, the needle assembly comprising:
• a needle;
• and
• a hub that is attached to the needle, the hub comprising:
• an inner cylindrical hub wall;
• a plurality of protrusions extending radially inward from the hub wall wherein a part of the needle is located inside the boundaries of the inner cylindrical hub wall,
• wherein the protrusions of the hub engage grooves of the needle mount, where the grooves comprise a first portion that defines a passageway substantially parallel to a longitudinal axis of the needle mount, and wherein part of the needle in the needle assembly is located within the boundaries of the inner cylindrical wall enters into the needle mount following the cylindrical axis, and
• ii) partially rotating the needle mount and the needle assembly relative to each other, wherein rotation of the needle mount and the needle assembly provides an audible clicking sound when the needle assembly fully is engaged with the needle mount.