Spi 21-283-7 Radius Contact Point Dial Indicator

Product Description

The SPI 21-283-7 is a radius-style contact point designed for use with dial indicators in precision measurement applications. Machined from steel, this contact point features a 4-48 thread size and a contact point length of 0.0313 inches, with an overall length of 0.3125 inches (5/16 inches). The radius tip geometry provides consistent, repeatable surface contact on curved or irregular workpiece surfaces, making it a reliable choice for metrology setups on the shop floor or in inspection environments. Installation and replacement are straightforward tasks performed by machinists, quality technicians, and tool and die professionals.

This contact point is suited for use in precision measurement tasks where a standard flat or ball-type point would yield inconsistent readings. The 4-48 thread is the industry-standard thread for AGD Group 1 dial indicators, making this a direct-fit replacement for worn or damaged contact points in most AGD-compliant indicators. It is appropriate for both surface plate inspection work and in-process gauging in machining and manufacturing environments.

Key Features

• Radius contact point style for consistent contact on curved surfaces
• Steel construction for durability and wear resistance
• 4-48 thread size compatible with AGD Group 1 dial indicators
• Contact point length of 0.0313 inches for compact tip geometry
• Overall length of 0.3125 inches (5/16 inches) for standard indicator reach

Compatibility

Designed for use with dial indicators conforming to AGD Group 1 standards with a 4-48 thread contact point mount.

Installation Notes

Contact point replacement on dial indicators requires no special tools beyond the contact point wrench appropriate for the indicator model. Power down or remove any electronic indicator from its measurement circuit before servicing. Do not overtighten the contact point, as this may damage the indicator spindle thread. Confirm thread engagement is secure before returning the indicator to service.