Starrett ( 268C) V-Blocks Pair with 1 Clamp [Misc.]Starrett V-blocks come in a variety of styles to suit the numerous requirements of machinists. They are for general shop use and layout work, as well as for holding stock in place during light-duty milling, drilling, and grinding operations. All the clamp screws have a hole in the head to make it easy to tighten down firmly on the work. The blocks are made of cast iron, each 1 1/2" (38 mm) square and 2" (50 mm) long. The clamp is ribbed for extra strength and will hold work up to 1 1/8" (28 mm) in diameter.