Spi 63-398-2 V-block Matched Pair 5 Inch 90 Degree

Product Description

The SPI 63-398-2 is a matched pair of cast iron V-blocks designed for precision workholding and inspection applications in machine shops and tool rooms. Each block features a 90-degree V angle with a maximum capacity of 5 inches, making it suitable for securing round, cylindrical, or hex workpieces during layout, grinding, milling, or measurement operations. The overall dimensions are 10 inches in length, 5 inches in width, and 6.5 inches in height. V parallelism is held to 0.0002 inches and V accuracy is rated at 0.0002 inches, reflecting the tight tolerances required for precision metrology and machining setups. Machinists, toolmakers, and quality control technicians are the primary users of this type of equipment.

This matched pair is suited for use in both production and inspection environments where repeatable, accurate workholding is required. Typical applications include shaft inspection, cylindrical grinding setups, surface plate layout work, and CMM fixturing. The cast iron construction provides rigidity and vibration damping, which is important when holding parts for precision measurement or light machining operations. The blocks are matched, meaning they are paired and lapped together to maintain consistent height and V geometry across both units, which is essential for supporting long or heavy cylindrical workpieces across two points.

Key Features

• 90-degree V angle accommodates round, hex, and cylindrical stock up to 5 inches in diameter
• Matched pair lapped to consistent height for two-point workpiece support
• V parallelism and V accuracy both held to 0.0002 inches for precision inspection use
• Squareness rated at 0.0012 inches per reference face
• Cast iron construction provides rigidity and vibration damping
• Non-magnetic design suitable for use near sensitive measuring instruments

Compatibility

Designed as a general-purpose matched V-block pair for use on surface plates, milling machine tables, and inspection fixtures where a 5-inch maximum capacity and 90-degree V geometry are required.

Installation Notes

V-blocks are typically set up by machinists or quality control technicians on a surface plate or machine table. Clean mating surfaces before placing the blocks to ensure accurate seating and prevent damage to reference faces. When clamping workpieces, use appropriate clamps or straps rated for the workpiece weight and do not exceed the stated maximum capacity of the V. Handle cast iron V-blocks carefully to avoid chipping the precision-ground faces, as damage to these surfaces will affect accuracy.