Vee-blocks consist of cast-iron pieces having gaps which are angular, similar to those in Fig. 280. When two such blocks are of the same shape and dimensions, they are named a pair, and are used to support a piece of work at a proper height above a surface-plate or table. A couple of vee-blocks are often used to support a rod or lever while being scribed ; for this purpose, the two blocks are put upon the table, and the piece of work is put into the gaps of both blocks, a scriber-block is then put to the work, and the scriber-point is adjusted to the desired height for the object of marking the lines required. The gap sides in vee-blocks are at an angle of about ninety degrees with each other, and are made wide enough to allow one pair of blocks to be used for a variety of work of different sizes; consequently, a thick lever or rod will fit the mouths of the blocks, and a smaller rod or other piece of work will fit some other portions of the gaps at a distance from the mouths or entrances. In Fig. 281, a pair of vee-blocks are shown on a surface-plate or table, this being the manner in which the blocks are generally used. The uses of scriber-blocks, vee-blocks, and tables, are closely connected, the three tools being necessary to scribe one piece of work.