Spi 63-397-4 V-block 4.5 in 90 Degree Cast Iron Matched Pair

Product Description

The SPI 63-397-4 is a cast iron V-block designed for precision workholding in metrology, inspection, and machining applications. The 90-degree V angle accommodates round stock up to 4.5 inches in diameter, making it suitable for supporting shafts, cylinders, and other cylindrical workpieces during layout, grinding, or inspection operations. V parallelism and V accuracy are both held to 0.0002 inches, ensuring consistent and repeatable positioning. This unit is sold as a matched pair, which is standard practice for setups requiring two-point support on a surface plate or machine table. Machinists, toolmakers, and quality control technicians are the primary users of this type of precision workholding equipment.

These V-blocks are used in tool and die shops, machine shops, and quality labs for cylindrical part inspection and layout work. Typical applications include checking runout, supporting workpieces during scribing or drilling, and aligning parts for CMM or surface plate measurement. The matched pair configuration ensures that both blocks share consistent geometry, which is critical when supporting a single workpiece across two contact points. No magnetic base is included or required for standard surface plate use.

Key Features

• 90-degree V angle for secure seating of round and cylindrical stock
• Maximum V capacity of 4.5 inches diameter
• V accuracy of 0.0002 inches for precise, repeatable positioning
• V parallelism held to 0.0002 inches (30 micrometers)
• Squareness of 0.0012 inches per measurement
• Sold as a matched pair for two-point cylindrical support setups
• Cast iron construction for rigidity and damping on surface plates and machine tables

Compatibility

Designed for use as a precision workholding accessory on surface plates, sine plates, and machine tables in standard tool room and inspection environments. No specific machine model compatibility is stated by the manufacturer.

Installation Notes

V-blocks of this type are placed and used by machinists and metrology technicians — no installation in the traditional sense is required, but setup on a surface plate should follow standard surface plate cleanliness and handling procedures. Ensure the contact surfaces of both blocks and the surface plate are clean and free of burrs or debris before placing the workpiece. When used as a matched pair, both blocks should be positioned on the same reference surface to maintain consistent support geometry. Do not use these blocks as clamping devices beyond their rated capacity.