Abstract: A threadedly engageable coupling device is used with a complementary coupling device for tightening first and second article pieces, and includes an abutment head, a cylindrical shank extending from the head, and a plurality of blade portions disposed on a proximate segment of the shank proximate to the head. Each of blade portions has a cutting edge which gradually deviates from the proximate segment when extending towards the head such that when the shank is inserted into a bore in the first article piece to permit the head to abut against the piece by a friction force generated through screw movement of a threaded surface of a distal segment of the shank and a threaded surface of the complementary coupling device, the cutting edge incrementally incises the first article piece so as to guard against rotation of the shank relative to the piece to thereby tighten the first and second article pieces together.