Osborne Copper Rivet & Bur Setter #12 You are looking at one brand new Osborne Copper Rivet and Bur Setter Size #12. This item 169-6 is a strong forged steel, case hardened setting tool with light knurled cross sections. Instructions: Push the rivet through the hole then turn the material over. Place the burr or washer on the rivet, then use the rivet setter's straight hole to drive the burr down against the material. Cut the rivet off close to the burr with side or end nippers. Do not cut off flush with the burr, but leave about 1/16 of an inch above the burr. The hole on the side of the rivet setter can be used to dislodge any waste that is weiged into the tool. Place the concave recess of the setter on the burr. Hold perpendicular and strike the end of the setter forcefully, turning to the left then right as you strike. This spreads the end of the rivet over the burr simultaneously rounding its end. A few extra blows from a soft faced mallet can be used to flatten the rivet end a bit, if desired.