Hertel 72309131 Chucking Reamer Letter M Cobalt Steel

Product Description

The HERTEL 72309131 is a cobalt steel chucking reamer designed to finish-ream holes to a Letter M diameter of 0.2950 inches. Built with six straight flutes and a right-hand cutting direction, it delivers consistent bore accuracy in ferrous and harder alloy workpieces. The straight-cylindrical shank seats securely in standard drill chucks and collets. At 6 inches overall length with a 1.5-inch flute length, this tool is well-suited for through-hole and blind-hole finishing operations on the mill, drill press, or lathe. The bright, uncoated finish makes wear inspection straightforward during production runs. Machinists and tool-and-die professionals reaching tight tolerances on close-fit holes are the primary users.

This chucking reamer is used in machine shop production and maintenance environments where holes must be brought to a precise final diameter. Typical applications include fixture bores, bushing seats, and shaft fits in both job-shop and production settings. The cobalt steel construction provides improved heat resistance compared to standard high-speed steel, making it a practical choice when reaming harder steels or running at elevated speeds without flood coolant. It ships as a single unit with no minimum order beyond one piece.

Key Features

• Letter M diameter (0.2950 inches) for precise final bore sizing
• Cobalt steel construction for improved heat and wear resistance over standard HSS
• Six straight flutes for smooth, consistent material removal
• Right-hand cutting direction compatible with standard machine spindles
• Straight-cylindrical shank fits common drill chucks and ER collets
• Bright, uncoated finish for easy wear monitoring

Compatibility

Designed as a machine chucking reamer for use in drill presses, lathes, knee mills, and CNC machining centers equipped with a drill chuck or straight-shank collet holder accepting a 0.2950-inch diameter tool.

Installation Notes

This reamer is installed by a machinist or tool-and-die technician. Power down the machine spindle and confirm zero motion before changing tooling. Secure the straight-cylindrical shank fully within the chuck or collet to the recommended grip depth to prevent runout. Always apply cutting fluid appropriate to the workpiece material, and allow reaming stock of 0.001 to 0.005 inches for best results — do not ream from a rough-drilled condition without an intermediate boring or drilling step.