Starrett 50140 Steel Square 24 Inch Blade

Product Description

The STARRETT 50140 is a precision steel square used for layout, inspection, and verification work in machining, fabrication, and toolroom environments. The blade measures 24 inches in length, and the base measures 12-5/16 inches, providing a stable reference edge for checking perpendicularity. Accuracy is rated at 0.0025 millimeters (0.000100 inches), making this tool suitable for close-tolerance work where a standard square will not meet inspection requirements. The body is constructed from steel throughout. Machinists, tool and die makers, fabricators, and precision inspectors are the primary installers and users of this instrument.

The STARRETT 50140 is intended for use in professional shop environments where flat and square reference checks are part of a standard quality workflow. Typical applications include checking machined surfaces, squaring vise jaws, setting up milling fixtures, and verifying right-angle reference during layout. The generous blade length makes it practical for larger workpieces and plate stock that a smaller square cannot span. This square is suited for both bench use and in-process inspection on the shop floor.

Key Features

• Blade length of 24 inches for coverage across large workpieces and plate stock
• Base length of 12-5/16 inches for a stable, wide footprint during use
• Accuracy of 0.0025 mm (0.000100 inches) for close-tolerance inspection and layout
• Full steel construction for durability and long-term dimensional stability
• No bevel edge design, providing a clean flat reference surface

Compatibility

Designed as a general-purpose precision layout and inspection square for use in machining, fabrication, and toolroom applications where a 24-inch blade length is required.

Installation Notes

This tool requires no installation in the mechanical sense, but proper handling is critical to maintaining its accuracy rating. Store the square in a protective case away from surfaces that could cause impact damage or burring of the reference edges. Clean reference surfaces and workpiece faces before use to prevent debris from introducing measurement error. Calibration should be verified periodically against a known reference standard, particularly if the square has been dropped or subjected to impact.