Self drilling blind rivet

Claim 1

A self drilling blind rivet comprising a hollow elongated rotatable one piece body of hardenable metal having flange means and torque receiving means formed therein at one end and having a thick second end with a hardened drill bit formed therein capable of drilling through metal parts, said torque receiving means enabling said body to be rotated whereby said drill bit may drill a hole through metal parts to be held together by the rivet, said body including a plastically deformable sleeve section extending between said flange means and torque receiving means and said drill bit and having a hardness significantly lower than said drill bit and low enough to enable it to be upset into a radial flange pleat by the application of axial compression to it whereby parts may be clamped between said flange means and said flange pleat, said body having a blind bore opening out of said one end, and a mandrel in and extending out of said bore and having a radially enlarged head located near the blind end of the bore and being slidable inside the bore, said sleeve section having a reduced diameter portion forming a radial shoulder engageable with said enlarged head for blocking removal of the mandrel from the bore and serving to transmit tension on the mandrel into axial compression on the sleeve section to enable said compression to cause it to collapse and form said flange pleat, said drill bit being a permanent part of the body and remaining integral with said body after said collapse of said sleeve section.