Starrett 70829 Radius Contact Point 4-48 2 Inch Solid Carbide

Product Description

The STARRETT 70829 is a drop indicator radius contact point designed for use with dial indicators in precision measurement applications. It features a solid carbide tip construction for wear resistance and dimensional stability across repeated use cycles. The contact point has an overall length of 2 inches (50 inches in millimeters: 50.80 mm contact point length, 50.00 mm overall length) and a tip diameter of 5.16 mm. The 4-48 threaded shank provides secure attachment to compatible indicator stems. Metrology technicians, machinists, and quality control professionals install and use this type of accessory during setup, inspection, and runout measurement tasks.

This contact point is suited for precision measurement environments where a radius-style tip is required to contact curved or contoured workpiece surfaces. It is compatible with AGD-standard dial indicators and back plunger dial indicator bodies. Typical applications include surface inspection, bore gauging setups, and machine tool alignment where consistent, repeatable contact geometry is critical. The solid carbide material extends service life compared to steel alternatives in high-cycle or abrasive contact conditions.

Key Features

• Radius-style contact point geometry for consistent contact on curved and contoured surfaces
• Solid carbide construction for high wear resistance and long service life
• 4-48 threaded shank for secure mounting to AGD-standard indicator stems
• 2 inch overall length with 5.16 mm tip diameter
• Compatible with 650 and 651 back plunger dial indicators as well as standard AGD dial indicators

Compatibility

Designed for use with 650 and 651 Back Plunger Dial Indicators and AGD Dial Indicators requiring a 4-48 threaded contact point.

Installation Notes

Installation is performed by metrology technicians or machinists. Before swapping contact points, remove the indicator from any active fixturing to prevent accidental loading or damage to the indicator stem. Thread the contact point into the indicator stem by hand first, then snug with the appropriate spanner or flat wrench — do not overtighten, as the 4-48 thread is fine and the carbide tip assembly can crack if torqued excessively. Verify seating and zero the indicator after any contact point change.