Precision Imperial 1-2-3 Block 2pcs Set Toughened and precision ground steel packing blocks with 5 tapped and 18 clearance holes allowing two or more blocks to be connected together in various configurations such as angle blocks, tee blocks, or used as a fixture to hold small parts for machining. Ideal when machining more than one part that has to move between machines or operations, just load a new block with part attached to keep reference between the operations. Can be used singly, as a pair or more to suit application. Specifications: SKU Size(HxWxL) Squareness Tolerance of Size No. Of Hole Thread 050-060-00500 1x2x3” 0.0003”/1” ±0.0002” 23 3/8” x 16TPI 050-060-00525 2x3x4” 0.0003”/1” ±0.0003” 23 3/8” x 16TPI 050-060-00550 2x4x6” 0.0003”/1” ±0.0005” 23 5/8” x 11TPI