Starrett 50136 Steel Square 12 in Blade 7 in Base

Product Description

The STARRETT 50136 is a precision steel square designed for layout, inspection, and verification work where accuracy is critical. With a 12-inch blade length and a 7-inch base length, this tool delivers an accuracy of 0.0001 inches (0.0025 mm), making it suitable for demanding trade and shop applications. The square is manufactured from steel for durability and dimensional stability across typical workshop and field conditions. Machinists, pipefitters, fabricators, and layout technicians rely on tools at this tolerance level when checking perpendicularity on machined parts, structural assemblies, or precision fabrications.

This square fits into workflows that require reliable 90-degree reference checks on flat or vertical surfaces. It is appropriate for use in machine shops, fabrication shops, mechanical contracting environments, and inspection stations. The 12-inch blade gives adequate reach for medium-scale workpieces, while the 7-inch base provides stable footing on a reference surface. It does not feature a bevel edge, keeping the geometry straightforward for standard squareness verification tasks.

Key Features

• 12-inch blade length for medium-range layout and inspection reach
• 7-inch base length for stable placement on reference surfaces
• Accuracy of 0.0001 inches (0.0025 mm) for high-precision squareness checking
• Steel construction for durability and dimensional stability
• No bevel edge — standard geometry for direct 90-degree reference work
• Complies with California Proposition 65 standards

Compatibility

Designed as an OEM-style precision layout square suitable for general machining, fabrication, and mechanical inspection applications requiring a 12-inch blade steel square.

Installation Notes

This tool is handled and used by machinists, pipefitters, and trade layout professionals — no power source or fasteners are required for use. Store and handle with care to protect the precision-ground edges from impact or corrosion, which can affect accuracy. Periodically verify the square against a known reference standard to confirm it remains within tolerance, especially after any drop or impact event.