Hertel 79889887 Chucking Reamer 0.251 in Solid Carbide

Product Description

The HERTEL 79889887 is a solid carbide chucking reamer designed for precision hole finishing in machined components. With a reamer diameter of 0.251 inches and a tight tolerance of 0.0000 to 0.0003 inches over nominal, this tool delivers consistent, repeatable sizing in production and job-shop environments. The straight flute geometry suits non-interrupted cuts in a range of ferrous and non-ferrous materials. At 3 inches overall length with a 1-inch flute length and a straight cylindrical shank, it mounts directly in standard drill chucks, collets, or floating holders on CNC machining centers and manual machines alike. Machinists and toolroom technicians are the primary users of this tool.

This reamer is suited for finishing pre-drilled or bored holes to a close tolerance in light to medium production runs. The 0.0003-inch over-size designation means it cuts slightly above nominal 0.2500 inches, making it appropriate for applications requiring a light press fit or controlled slip fit. It is classified as an over-size reamer and is not intended as a standard dowel pin reamer. Typical applications include aerospace components, hydraulic manifolds, fixture plates, and general precision machined parts where hole diameter control is critical.

Key Features

• Solid carbide construction provides rigidity and wear resistance compared to HSS alternatives
• 0.0000 to 0.0003 inch over-size tolerance for predictable, repeatable hole sizing
• 4-flute straight geometry for clean, chatter-resistant cuts in through and blind holes
• Bright uncoated finish suitable for use with cutting fluids across a broad range of workpiece materials
• Straight cylindrical shank compatible with standard chucks, collets, and floating holders
• Right-hand cutting direction for conventional spindle rotation

Compatibility

Designed as an over-size chucking reamer for use in CNC machining centers, turret lathes, and manual drill presses equipped with standard straight-shank toolholding. No specific machine model compatibility data was provided by the manufacturer for this part.

Installation Notes

This tool is installed by a machinist or toolroom technician. Ensure the machine spindle is fully stopped and the tool is secured with adequate clamping force in the holder before starting the cut. Use appropriate cutting fluid for the workpiece material to extend tool life and maintain surface finish. Always ream to a previously drilled or bored hole sized to leave the correct stock allowance for reaming.