1 Pair of Matched 1 x 2 x 3 Accuracy Parallel Blocks, 23-Hole 0.0002 Inch Alloy Steel 1 2 3 Parallel Block Set

1" x 2" x 3" 23-Hole Matched Accuracy Parallel Blocks, 40Cr SteelSpecification:Hole: 23Size: 1" x 2" x 3"Material: 40Cr SteelHardness: HRC55-62Squareness: 0.0003"/1"Tolerance of Size: 0.0002"Thread Holes: 5 - (3/8 "-16)Untapped Holes: 18 - (9mm)Features:With 5 threaded holes (3/8"-16) for bolting, drilling, hammering or other purposes.This is a set of 123 parallel blocks containing two that you can use to assemble into other shapesThe parallel blocks are packed in cartons with a layer of rust-proof wax paper, which is easy to clean and has a good surface finish.Accuracy machine block milling machine, very suitable for machinists, woodworking, metal working work, accurate and easy to clean.Package Includes:2 x 1" x 2" x 3" Accuracy Parallel BlocksNOTE:The inner diameters of the 23 parallel spacer blocks' smooth holes are 8.9mm. The non-threaded smooth holes are special structural holes designed for weight reduction and stress release during heat treatment. They cannot be passed through screws with an outer diameter of 9.525mm. The threaded holes of the spacer blocks are suitable for screws with an outer diameter of 9.525mm, and are specifically used for multiple pieces to be connected and locked together. If you need to pass through the smooth holes during install, you must use bolts with a rod diameter smaller than 8.9mm. It is strictly prohibited to insert large-sized screws.

• Material: Made of 40Cr steel, which is an alloy steel with good comprehensive mechanical properties and is currently one of the most widely used steels in the machinery manufacturing industry
• Dimensions and Accuracy: The three sides are 1, 2 and 3 respectively, the tolerance of size is about 0.0002, the squareness is about 0.0003/1
• Holes: There are 23 holes in the block, 5 are threaded holes, which are used for clamping, the remaining 18 are untapped holes, 5 threaded holes are 3/8-16 in size, and the other 18 holes are 9mm in diameter
• Design: Accuracy grade tool steel was quenched and ground on all six sides of the block
• Features: Cross drilling design for minimum weight and maximum strength