The base is hex-shaped, so the block to be held rigidly in a vise.. Made from alloy steel, hardened, and ground, top and bottom. This block weighs five pounds (2.3kg).
Bench Block, 4-7/8" Diameter x 1-1/2" High with Ten Oversize Holes from 1/8-7/8" Diameter and Two V-Grooves at Right Angles. 4-7/8" (120mm) Diameter x 1-1/2" (38mm) High with Ten Oversize Holes from 1/8-7/8" (3-22mm) Diameter and Two V-Grooves at Right Angles Heavy-Duty 4 7/8" (120mm) Diameter Angles.