Aluminum is crimped into the unilok grooves of the shaft to prevent unscrewing. This is a generic replacement driver with o-ring for the Hitachi NR83A, NR83A2, NR83A2(S) framing guns.Aftermarket Hitachi Framing Nailer Piston Driver.
. Aftermarket Piston Driver for Hitachi NR83A + A2 Replaces 890385, 885915 (S7 Steel) Guaranteed never to unscrew.Aftermarket Hitachi Framing Nailer Piston Driver. Aluminum is crimped into the unilok grooves of the shaft to prevent unscrewing.