Spi 91-332-7 Drop Indicator Spindle Square

Product Description

The SPI 91-332-7 is a drop indicator spindle square designed for use with dial indicators in precision measurement applications. This accessory mounts to a dial indicator spindle and establishes a square reference plane, allowing technicians and machinists to take accurate perpendicularity and surface measurements. With a graduation resolution of 0.00050 decimal inch, it delivers the fine measurement capability required for close-tolerance inspection work. It is installed and used by machinists, tool-and-die technicians, and quality control personnel working in machine shops, manufacturing environments, and precision assembly operations.

The SPI 91-332-7 spindle square is suited for use in metrology and inspection setups where a dial indicator must be oriented perpendicular to a reference surface. Typical applications include checking squareness of machine tool setups, inspecting part geometry on surface plates, and verifying fixture alignment. This accessory is compatible with dial indicators and is commonly used alongside surface plates, granite tables, and magnetic indicator bases in production and quality assurance workflows.

Key Features

• Graduation resolution of 0.00050 decimal inch for precise perpendicularity measurement
• Spindle square accessory type — mounts directly to dial indicator spindle
• Designed for use with standard dial indicators
• Compact and lightweight at 2 pounds for easy handling during inspection setups

Compatibility

Designed for use with dial indicators. No specific compatible model numbers or system families were provided by the manufacturer for this part.

Installation Notes

Installation is performed by machinists or metrology technicians familiar with dial indicator accessories. Ensure the dial indicator spindle is clean and free of debris before mounting the spindle square. Verify that the accessory is fully seated and secure before taking measurements to avoid false readings. No special tools or electrical shutoffs are required for this mechanical accessory.