Spi 77-634-4 Beveled Straight Edge 48 Inches Spring Steel

Product Description

The SPI 77-634-4 is a single-bevel straight edge designed for precision layout, inspection, and surface verification in machine shops, tool rooms, and fabrication environments. Manufactured from spring steel, this straight edge measures 48 inches long, 2-13/32 inches wide, and 3/8 inches thick. Edge flatness is held to 0.0011 inches (25 micrometers) and parallelism to 0.0020 inches (50 micrometers), making it suitable for applications where accuracy and repeatability matter. Machinists, toolmakers, and quality control technicians use this tool when checking flatness, scribing lines, or verifying surface geometry on workpieces and machine tables.

This straight edge is suited for precision inspection and layout work in industrial and manufacturing settings. It is appropriate for use on surface plates, machine beds, and large workpieces where a long reference edge is required. The 48-inch length covers a wide working span, and the beveled single edge allows the technician to establish a precise reference line or check for surface deviation with minimal contact area. It is commonly found in tool rooms, quality labs, and production floor inspection stations.

Key Features

• Edge flatness of 0.0011 inches (25 micrometers) for reliable precision reference
• Parallelism held to 0.0020 inches (50 micrometers)
• Single beveled edge design reduces contact area for accurate line transfer and inspection
• Spring steel construction resists deflection and wear under regular shop use
• 48-inch working length accommodates large workpieces and machine surfaces
• Compact 3/8-inch thickness keeps the tool lightweight and easy to handle

Compatibility

Designed as a general-purpose precision straight edge for use in machine shop, tool room, and quality inspection applications requiring a 48-inch beveled reference edge.

Installation Notes

Handle with care to avoid nicking or distorting the beveled edge, as damage will compromise accuracy. Store flat or hang vertically to prevent warping over time. Clean the edge and workpiece surface before use to remove chips, oil, or debris that could affect readings. This tool requires no installation but should be periodically checked against a certified reference standard to verify it remains within tolerance.