Hertel 72308398 Chucking Reamer Size 39 Cobalt Steel

Product Description

The HERTEL 72308398 is a wire-gauge chucking reamer sized at number 39, ground to a diameter of 0.0995 inches and manufactured from cobalt steel. It is designed to finish-ream drilled holes to a precise tolerance in ferrous and hard materials where high-speed steel would wear prematurely. The straight, four-flute geometry produces a clean bore surface with right-hand cutting action. Overall length is 3 inches with a 7/8-inch flute length. The straight-cylindrical shank seats directly in a drill chuck or collet, making it a straightforward drop-in for machine or hand-held power tool use. Machinists, tool and die workers, and maintenance technicians install this reamer for close-tolerance hole finishing on the shop floor.

This chucking reamer is suited for light finishing cuts in small-diameter bores, typically in metal fabrication, toolroom work, and precision maintenance applications. The number 39 wire-gauge size targets bore diameters in the 0.0500 to 0.0999-inch range, with the finished reamed diameter landing at 0.0995 inches. The bright, uncoated finish keeps the tool ready to use as received without additional prep. It is appropriate for both manual and CNC drilling operations where repeatable hole size is required.

Key Features

• Cobalt steel construction for improved wear resistance and heat tolerance compared to standard high-speed steel
• Finished reamed diameter of 0.0995 inches, wire size number 39
• Four straight flutes with right-hand cutting direction for smooth, consistent material removal
• Bright, uncoated finish suitable for immediate use out of the package
• Straight-cylindrical shank for direct chuck or collet mounting without adapters
• Compact 3-inch overall length with 7/8-inch flute length for small-bore applications

Compatibility

Designed as an OEM-style chucking reamer for use in standard drill chucks and collets that accept a straight-cylindrical shank at the number 39 wire-gauge diameter.

Installation Notes

Chucking reamers should be installed by a qualified machinist or toolroom technician. Power down and de-energize the machine spindle before seating or removing the tool from the chuck or collet. Use a reaming allowance appropriate for the material being cut and avoid forcing the reamer at excessive feed rates, which can cause chatter or oversizing. Apply cutting fluid compatible with cobalt steel tooling when reaming ferrous materials to extend tool life and improve finish quality.