Patent ID: 7802952

Claim:
A combination comprising: a hard metal material workpiece having a hardness of at least 25 Rc, said hard metal material workpiece having an aperture which defines an aperture wall having a first diameter; and a rivetless nut plate assembly which is configured for installation into said aperture of said hard metal material workpiece, said installation being effected by pulling a stem through said rivetless nut plate assembly, said rivetless nut plate assembly comprising: a nut; a holding bracket, wherein the holding bracket is generally Y-shaped and comprises a tubular portion which extends into the aperture of the workpiece and a bracket portion which extends outwardly from the tubular portion; a retainer which engages the bracket portion of the holding bracket and retains the nut on the holding bracket; and a sleeve member having an outside surface which has a second diameter, said second diameter of the sleeve member being slightly larger than said first diameter of the aperture wall, said sleeve member being positioned around the tubular portion of the holding bracket, wherein the sleeve is made of at least one of Titanium Columbium, Monel, a soft Nickel alloy and a soft Titanium alloy, said sleeve member configured to engage the aperture wall in an interference fit prior to the pulling of the stem through the assembly and, thereafter, to be radially expanded upon the pulling of the stem through the assembly.