A blood collection assembly includes a hub with a distal end, a proximal end, a hub outer surface and an internal opening extending therethrough. The assembly also includes a holder housing defining a receiving chamber and having a rearward end adapted to receive a sample collection tube within the chamber and a forward end including a receiving port extending into the chamber, where the receiving port receives a portion of the proximal end of the hub therein. An internal opening of the hub accommodates a puncturing element at the proximal end thereof for providing passage of a fluid therethrough, and the puncturing element contacts the sample collection tube. The hub and the holder housing include an interengaging structure extending substantially perimetrically therearound for axially locking the hub with the holder housing.
