Spi 13-198-7 Steel Parallel Set 6 X 3/4 X 1/2 Inch

Product Description

The SPI 13-198-7 is a matched pair of precision-ground steel parallels designed for use in machining, grinding, and inspection setups. Each parallel measures 6 inches long, 3/4 inch high, and 1/2 inch thick, with all four faces precision ground to a parallelism tolerance of 0.0003 inches and a squareness tolerance of 0.0005 inches. Manufactured from high-grade hardened tool steel at 50 Rc hardness, these parallels provide a stable, repeatable reference surface for workholding and part location on mill tables, surface grinders, and CMM fixtures. Machinists, tool and die makers, and quality technicians rely on matched parallel sets like this for consistent part setup across production runs.

This parallel set is suited for use in precision machining environments where accurate workholding is critical. Common applications include elevating workpieces on magnetic chucks or vise jaws during surface grinding, supporting parts during milling operations, and providing reference datums during dimensional inspection. The matched pair configuration ensures both parallels are within tolerance of each other, making them interchangeable within the same setup without introducing measurable variation.

Key Features

• Matched pair — both parallels ground to the same tolerance for interchangeable use
• Four-face precision ground construction for versatile orientation in the setup
• 0.0003 inch parallelism tolerance for high-accuracy workholding
• 0.0005 inch squareness tolerance supports reliable right-angle referencing
• 50 Rc hardness resists wear and maintains dimensional stability over time
• High-grade hardened tool steel construction

Compatibility

Designed as a standard matched parallel set suitable for use with milling vises, surface grinder magnetic chucks, and inspection fixtures requiring a 6 inch by 3/4 inch by 1/2 inch reference block.

Installation Notes

Parallels should be cleaned and demagnetized before use to prevent chips or swarf from affecting seating accuracy. Always verify that the parallel is fully seated against the vise jaw or fixture surface before indicating or clamping the workpiece. Handle precision ground surfaces with care to avoid nicks or corrosion — store with a light coat of rust-preventive oil when not in use. No power source or mechanical fasteners are required for installation.