Osg 300-3125 Chucking Reamer 5/16 in Solid Carbide

Product Description

The OSG 300-3125 is a solid carbide chucking reamer designed for precision hole finishing in general machining applications. With a 5/16-inch (0.3125-inch) diameter and a tight tolerance of +0.0001 to +0.0005 inches, this reamer delivers accurate, consistent bore sizes in a single pass. The straight flute geometry and right-hand cut make it well suited for through-holes in a wide range of materials. It features a straight cylindrical shank for secure chuck retention and a 3-1/4-inch overall length with a 1-1/8-inch flute length. Machinists and tool room technicians are the primary users of this tool.

The OSG 300-3125 is intended for general machining environments including job shops, production floors, and maintenance tool rooms. It is used to bring drilled or bored holes to a finished diameter with controlled surface finish and dimensional accuracy. The straight flute design performs reliably in ferrous and non-ferrous materials. No coolant-through capability is present, so external flood or mist cooling is recommended when operating at higher spindle speeds or in tougher workpiece materials.

Key Features

• Solid carbide construction provides rigidity and wear resistance for long tool life
• Diameter tolerance of +0.0001 to +0.0005 inches supports tight-tolerance hole finishing
• Six-flute straight configuration delivers smooth cutting action and good chip clearance
• Bright/uncoated finish — compatible with a wide range of cutting fluids without coating interaction
• Straight cylindrical shank fits standard drill chucks and collet holders
• Series 300D — OSG standard carbide reamer line for general machining use

Compatibility

Designed as a standard solid carbide chucking reamer for general machining applications requiring a 5/16-inch finished bore diameter. Compatible with any machine tool spindle or lathe tailstock equipped with a chuck or collet capable of holding a straight cylindrical shank.

Installation Notes

Chucking reamers are installed by machinists in drill presses, CNC machining centers, turret lathes, or manual mills. Secure the straight shank firmly in a precision collet or drill chuck before use, and verify runout is within acceptable limits to maintain diameter tolerance. Pre-drill or bore the hole to within 0.005 to 0.015 inches of finished diameter before reaming — do not use the reamer as a primary material-removal tool. Apply appropriate cutting fluid for the workpiece material, as this tool does not support internal coolant delivery.