95WNIFE tungsten bucking bar price which density is 18.0g/cm3 is 255.00USD/PC on Mar. 28, 2019. The rivet block forms bucktails on rivets and comes in many different shapes and sizes. The particular shape to be used depends upon the location and accessibility of the rivet to be driven. Its size and weight depend on the size and alloy of the rivet to be driven. Under certain circumstances, and for specific rivet installations, specially designed bucking bars are manufactured locally.