On orderpicking trucks a "pallet grab" secures the platform, cart or other pallet substitute to the equipment. The trucks are designed to work with standard wood pallets and most often have "teeth" that compress into the middle stringer. You may find platform designs that offer a steel bar to latch onto, I would suggest the effectiveness of the grab mechanism will be diminished trying to secure this metal on metal design.
Most units on this site utilize either a hardwood or a laminate piece of wood to better mimic the intended design simulating a wood pallet. Some have found the laminate to last longer.