Under the screw head. The 2D fastener sits right on the board. Ron AC7AC K2 # 1289 -----Original Message----- I just want to clarify how to install the 2-D fasteners to the RF board. On P.33 Elecraft say to install these with 2 chssis screws and 2 lock washers. Do the lock washers go in between the 2D Fastener and the board, or the screw head and the board? Cheers, Dave.