Spi 77-647-6 Square Straight Edge 96 Inches Spring Steel

Product Description

The SPI 77-647-6 is a square straight edge precision layout and inspection tool manufactured from spring steel. At 96 inches in overall length, this straight edge is sized for large-scale surface verification, layout work, and flatness checking across extended workpieces. The square edge type provides a true reference surface with an edge flatness tolerance of 0.0018 inches (46 micrometers) and a parallelism tolerance of 0.0036 inches (92 micrometers). These tolerances make it appropriate for precision inspection and layout tasks in machine shops, fabrication facilities, and industrial maintenance environments. Machinists, toolmakers, and precision inspectors are the primary users of this tool.

This straight edge is suited for applications requiring a long, rigid reference surface. Typical uses include checking the flatness of machine beds, surface plates, welding tables, and large structural components. The 96-inch length accommodates wide or extended workpieces that smaller straight edges cannot span. Spring steel construction provides durability and resistance to flex under its own weight, which is important for maintaining accuracy across a full 96-inch span. The 3-5/32 inch width and 19/32 inch thickness provide adequate cross-sectional rigidity for consistent results.

Key Features

• 96-inch overall length for large-surface layout and inspection
• Edge flatness of 0.0018 inches (46 micrometers) for precision reference work
• Parallelism tolerance of 0.0036 inches (92 micrometers)
• Spring steel construction for durability and flex resistance
• Square edge type provides a consistent, well-defined reference surface
• 3-5/32 inch width and 19/32 inch thickness for cross-sectional rigidity

Compatibility

Designed as a general-purpose precision straight edge for use in machine shop inspection, industrial layout, and surface verification applications requiring a 96-inch reference tool.

Installation Notes

This tool is handled and used by machinists, toolmakers, and precision inspectors. Store the straight edge horizontally or hang it vertically from the designated hole to prevent warping over time. Clean contact surfaces before use to avoid debris-induced measurement error. Do not use this tool as a cutting guide or apply lateral force that could introduce permanent set into the spring steel.