Spi 98-453-4 Steel Parallel Set 6 X 3/4 X 1/8 Inches

Product Description

The SPI 98-453-4 is a matched pair of hardened steel precision parallels designed for use in machining, grinding, and inspection setups. Each parallel measures 6 inches long, 3/4 inch high, and 1/8 inch thick. All four faces are precision ground to a squareness tolerance of 0.0005 inches per 1 inch, and the steel is hardened to 50 Rc. These parallels are sold as a matched pair, making them suitable for applications that require consistent and repeatable workpiece support or reference surfaces in a machine vise or on a surface plate.

Precision parallels of this type are used by machinists, toolmakers, and metrology technicians in both job shop and production environments. They support workpieces at consistent heights inside milling vises, grinding fixtures, and inspection setups. The 1/8 inch thickness and 3/4 inch height make this pair well suited for tight-clearance vise work where thinner support stock is needed. Sold as a matched pair, both pieces are ground to the same dimensional tolerances, ensuring uniform lift and true seating across the workpiece.

Key Features

• Four-face precision ground construction for accurate seating on any face
• Squareness tolerance of 0.0005 inches per 1 inch for reliable reference surfaces
• Hardened to 50 Rc for wear resistance and dimensional stability
• High-grade hardened tool steel material
• Sold as a matched pair for consistent, repeatable setups
• Compact 1/8 inch thickness suits tight-clearance vise and fixture applications

Compatibility

Designed as a standard precision parallel for use in milling vises, surface grinders, and inspection fixtures where a 6-inch by 3/4-inch by 1/8-inch profile is required.

Installation Notes

Precision parallels are placed and removed by hand inside machine vises or on surface plates. Keep surfaces clean and free of chips or burrs before placing parallels to maintain seating accuracy. Handle with care to avoid nicks or corrosion on ground faces, as surface damage will affect squareness and repeatability. Store in a dry location or with a light coat of rust-preventive oil when not in use.