A quill tube is provided. The quill tube includes a hollow body and a spherical head. The hollow body defines a bore within the quill tube. The bore is configured to direct a flow of fuel into a fuel injector. The spherical head is located at a first end of the hollow body. The spherical head includes a tip, a first surface and a second surface. The tip is located at a distal end of the spherical head. The first surface is configured to engage with the fuel injector. The second surface is positioned between the tip and the first surface. Further, a flange is located proximate to the spherical head. The flange is angularly positioned relative to the first surface. If the spherical head is contacted against an external surface, the flange is configured to cause the second surface to touch the external surface.