One Two Three Block Set In Hardened Tool Steel RC 56 60 Precision Ground On All Six Sides For Ultra Flatness And Squareness 11 Hole Universal Block System Matched Pair Two Each For Machinists And DIY Pros
✔️ Precision-ground; RC 56-60; matched pair; 11 holes; square edges
Two precision-ground blocks, forged from hardened tool steel (RC 56-60), measure 2 x 3 inches on the main face with a 1 x 2 inch secondary face (50.8 x 76.2 mm and 25.4 x 50.8 mm). The blocks are matched in pairs to tight tolerances and feature an 11-hole pattern to accept fasteners and allow conversion to angle plates and fixtures. These handy references are essential for machinists and DIY pros when building jigs and fixtures on benches and milling tables.
✅ Material: hardened tool steel RC 56-60
✅ Overall size: 2" x 3" main face; 1" x 2" secondary face (50.8 x 76.2 mm and 25.4 x 50.8 mm)
✅ Flatness and parallelism: ±0.0001" (±0.0025 mm)
✅ Squareness: ±0.0003" per inch (±0.0076 mm per inch)
✅ Hole pattern: 5 x 5/16-18 tapped holes on faces plus 6 x 3/8" through holes with 1/2" counterbores
✅ Matched pair tolerance: 0.0002" (0.005 mm)
✅ Weight: ~492 g per block (1.07 lb)
Two-piece set for reliable pairing
💡 What is a 123 block used for in machining setups and fixture building? They are handy references for aligning and squaring workpieces in fixtures and jigs. They provide a solid base for repeatable setups and quick conversion to angle plates. In practice, they reduce setup time and increase accuracy in bench work and milling operations. - handy for squaring and validating fixtures and jigs - helps maintain parallel and perpendicular references across setups - supports quick conversion to angle plates and other fixtures - built from hardened tool steel for long life in a tough shop environment