Spi 13-672-1 2-3-4 Setup Block Matched Pair Hardened Steel

Product Description

The SPI 13-672-1 is a matched pair of 2-3-4 setup blocks machined from hardened steel and used for precision workholding, fixturing, and layout tasks in machine shops and toolrooms. Each block measures 2 inches wide by 3 inches long by 4 inches tall and holds a squareness tolerance of 0.0003 inches, with an overall dimensional tolerance of 0.0002 inches. Surface hardness runs 55 to 60 HRC, providing resistance to wear and deformation under repeated clamping and grinding operations. Machinists and toolmakers rely on these blocks to square vises, set up milling fixtures, and establish reference datums on surface plates.

2-3-4 blocks are standard toolroom equipment used across precision machining, grinding, inspection, and assembly operations in both job shops and production environments. This matched pair is suited for applications requiring two blocks of verified dimensional consistency, such as parallel setups on a milling table or bilateral support under a workpiece during surface grinding. The blocks accept 3/8-16 tapped holes and 3/8-inch untapped through holes, allowing clamping, stacking, and accessory attachment in a wide variety of fixturing configurations.

Key Features

• Matched pair — both blocks verified to the same dimensional and squareness standards
• Squareness tolerance of 0.0003 inches for precise angular reference
• Overall dimensional tolerance of 0.0002 inches
• Hardened steel construction at 55 to 60 HRC for long service life
• 5 tapped holes sized 3/8-16 for clamping and accessory attachment
• 18 untapped holes at 3/8 inch diameter for through-bolt and stacking configurations
• Standard 2 x 3 x 4 inch geometry for compatibility with common fixturing systems

Compatibility

Designed as a standard 2-3-4 setup block matched pair suitable for use with common milling, grinding, and inspection fixturing systems that accept 3/8-inch hole patterns.

Installation Notes

Setup blocks are installed by machinists and toolmakers — no licensed trade certification is required, but proper metrology practice applies. Clean all mating surfaces and the machine table or surface plate before placing the blocks to prevent burrs or debris from introducing measurement error. Do not use setup blocks as a substitute for precision ground parallels in applications requiring flatness tolerances tighter than the block specification. Deburr and stone any nicks on block faces before use to maintain squareness accuracy.