Starrett 51440 Square Straight Edge 24 in Steel

Product Description

The STARRETT 51440 is a precision square straight edge designed for layout, inspection, and reference work requiring a reliable flat reference surface. Measuring 24 inches in length, 1-13/32 inches in width, and 11/64 inches in thickness, this steel straight edge delivers an edge flatness of 0.0004 inches and a parallelism tolerance of 0.0008 inches. It is suited for machinists, toolmakers, and quality control technicians who need consistent, repeatable linear reference in shop or inspection environments. The all-steel construction provides rigidity and resistance to wear under regular production or bench use.

This straight edge is used in metalworking, fabrication, and precision measurement applications where a flat, square reference edge is required. Common tasks include checking surface flatness, scribing layout lines, verifying straightness of machined edges, and supporting inspection setups. It is appropriate for both production floor environments and dedicated metrology or inspection rooms. Trade professionals in machining, toolmaking, and general metalworking fabrication routinely rely on this type of precision straight edge for surface plate and bench work.

Key Features

• Edge flatness of 0.0004 inches for precision reference and inspection work
• Parallelism tolerance of 0.0008 inches ensures consistent measurements across both edges
• Steel construction provides durability and dimensional stability under shop conditions
• 24-inch working length covers a wide range of layout and verification tasks
• Compact 11/64-inch thickness allows use in confined setups without bulk

Compatibility

Designed as a general-purpose precision straight edge for use in standard metalworking, machining, and inspection applications where a flat steel reference edge is required.

Installation Notes

Straight edges are handled and positioned by machinists or quality control technicians and require no permanent installation. Store and handle the straight edge carefully to avoid nicks or burrs on the reference edges, as contact damage will compromise measurement accuracy. Clean the reference edge and work surface before use to remove chips, oils, or debris that could affect readings. Follow applicable shop metrology procedures and calibration schedules to maintain accuracy.