The DF 16 rebar tier provides contractors increased speed, efficiency, and ease of binding concrete reinforcing steel. The rebar tier is a mechanical unit that allows the operator to tie up to 1000 knots/hour. To tie rebar, the operator places the unit on the reinforcing steel and uses one hand to press it down, releasing a tie wire that is instantly wrapped and tied around the rebar. Wacker Neuson. 800-770-0957.