Both the head piece 249B, and the tail piece -249C are made of solid brass.
Item 250 Screw Clamp is 3" long and is nickel plated.

249-Screw clamp with head plate -$26.24 - Currently out of stock
249A- Screw clamp with tail plate -$23.80
249B -Head Plate-$10.32
249C- Tail Plate -$7.92
250- Screw Clamp -$15.92