Hertel 79890778 Chucking Reamer Size 42 Solid Carbide

Product Description

The HERTEL 79890778 is a solid carbide chucking reamer designed for precision hole finishing in metalworking and machining applications. Ground to wire size 42 (0.0935 inches decimal), this reamer holds a tight diameter tolerance of 0.0000 to 0.0002 inches, making it well suited for jobs that require close-tolerance bore sizing. The straight flute geometry and right-hand cutting direction provide clean, consistent material removal in through-holes and blind-hole applications. At 2 inches overall length with a 1/2-inch flute length, this is a compact tool built for small-bore work. It is installed and used by machinists and tool-room technicians operating CNC machining centers, drill presses, and manual lathes.

This chucking reamer is used in production machining and tool-room environments where small-diameter hole finishing is required. The bright uncoated solid carbide construction makes it appropriate for use in a range of ferrous and non-ferrous materials where a high-hardness cutting edge is needed. The straight cylindrical shank fits standard collets and chucks without modification, keeping setup time low. Typical applications include reaming precision pin holes, dowel holes, and close-tolerance bores in dies, molds, and machined components. The four-flute design promotes chatter-free cutting and good surface finish at the bore wall.

Key Features

• Wire size 42 diameter: 0.0935 inches decimal equivalent
• Solid carbide construction for extended tool life and rigidity in small-diameter work
• Diameter tolerance of 0.0000 to 0.0002 inches for tight-tolerance bore finishing
• Four straight flutes with right-hand cut for smooth, consistent material removal
• Bright uncoated finish — no coating buildup concerns on close-tolerance diameters
• Straight cylindrical shank fits standard collets and drill chucks

Compatibility

Designed as an OEM-style chucking reamer for use in standard collet chucks and drill chucks accepting a straight cylindrical shank at this diameter range. Verify spindle and collet clearance before installation.

Installation Notes

Chucking reamers are installed by machinists in collet chucks or drill chucks on CNC machining centers, drill presses, or lathes. Always bring the spindle to a full stop and lock out the machine before changing or inspecting tooling. Use cutting fluid appropriate for the workpiece material to prolong tool life and maintain bore finish quality. Solid carbide is brittle — avoid side-loading or interrupted cuts that can chip the cutting edges.