HHIP Hex and Square ER Collet blocks are versatile, precision-machined tool holding devices used in CNC machining and other milling applications expediting set-up time. Constructed from hardened and ground tool steel with exceptional precision (within .0005-inch flatness, squareness, and parallelism), these blocks provide a stable and accurate work holding surface. These blocks are adaptable for holding parallel, square, or hexagonal workpieces. They are also useful for cross hole drilling at angles of 60, 90, or 120 degrees. This versatility allows for a wide range of machining tasks. The block may be used horizontally or standing upright which can be advantageous for specific machining operations and setups. Square and Hex ER Collet blocks are engineered to work seamlessly with standard ER collets. This ensures that a variety of tool sizes can be accommodated, providing flexibility in tool selection. The 11/16-inch through hole is beneficial for machining long workpieces. This feature allows the tool to pass through the block, facilitating operations on extended parts. The ER nut is included with the block, which is essential for securing the ER collet in place, ensuring a firm grip on the cutting tool. Block is 1-3/4 x 1-3/4. The overall height with the ER nut is shown in the chart.