Spi 13-216-7 Steel Precision Parallel 6x1-3/4x1/4 Matched Pair

Product Description

The SPI 13-216-7 is a matched pair of steel precision parallels designed for use in machining, inspection, and setup applications. Each parallel measures 6 inches long, 1-3/4 inches high, and 1/4 inch thick, with all four faces precision ground to a parallelism tolerance of 0.0003 inches and a squareness of 0.0005 inches. Manufactured from high-grade hardened tool steel at 50 Rc hardness, these parallels deliver the rigidity and dimensional accuracy required for reliable workholding and part inspection on surface plates, milling machines, and grinding setups.

These parallels are suited for tool rooms, machine shops, and quality control environments where consistent and repeatable part positioning is critical. Typical applications include supporting workpieces during milling or grinding operations, checking flatness on a surface plate, and establishing reference datums during inspection. The matched pair configuration allows technicians to use both parallels simultaneously for balanced workpiece support, a common requirement in precision fixturing and CMM setups.

Key Features

• Parallelism tolerance of 0.0003 inches for high-accuracy setups
• Squareness tolerance of 0.0005 inches across all four faces
• Four faces precision ground for maximum surface contact and stability
• High-grade hardened tool steel at 50 Rc for wear resistance and dimensional stability
• Sold as a matched pair for balanced workpiece support
• Compact 1/4-inch thickness fits tight clearance applications

Compatibility

Designed as a general-purpose precision parallel for use with standard milling machines, surface grinders, surface plates, and inspection fixtures where workpiece support and datum referencing are required.

Installation Notes

Precision parallels are typically placed and positioned by machinists or tool and die makers during machine setup or inspection. Clean all mating surfaces thoroughly before use to prevent contamination from affecting accuracy. Store parallels in a protective case or designated holder to prevent nicking or corrosion of the ground surfaces. Do not use parallels as striking tools or clamp directly against the ground faces with excessive force.