Onsrud 57-300 Downcut Spiral Router Bit 5/16 in Solid Carbide

Product Description

The ONSRUD 57-300 is a downcut spiral router bit machined from solid carbide and designed for precision routing in natural wood, solid surfaces, and wood composites. With a 5/16-inch (0.3125 inches) cutter diameter and a 1.125-inch length of cut, it delivers clean, downward shear action that keeps the top face of the workpiece free of tearout and fiber lifting. The 30-degree helix angle and double-edge geometry promote efficient chip evacuation while maintaining edge quality. At 3 inches overall length and 0.1 pounds, it seats in standard router collets without adding excessive mass. This bit is typically installed and operated by CNC router technicians and woodworking professionals.

The 57-300 is suited for production and shop environments routing natural wood panels, solid-surface countertop materials, and wood composite sheet goods. Its downcut flute geometry makes it a preferred choice for top-surface-critical operations such as dadoes, slots, and profile cuts where surface finish on the show face matters. The 1.875-inch shank length provides stable tool engagement in the collet during full-depth passes through sheet material. Right-hand cutting direction is compatible with standard CNC router spindle rotation.

Key Features

• Downcut flute design suppresses tearout on the top face of the workpiece
• Solid carbide construction for rigidity and extended edge retention compared to HSS
• 30-degree helix angle with double-edge geometry for balanced cutting forces
• Uncoated finish suitable for natural wood and solid-surface applications
• Right-hand cutting direction compatible with standard router spindle rotation
• 1.875-inch shank length for secure collet engagement

Compatibility

Designed for use in CNC routers and hand-held routers accepting a 5/16-inch shank collet. Material applications include natural wood, solid surfaces, and wood composites per manufacturer specification.

Installation Notes

Installation should be performed by a qualified CNC technician or experienced router operator. Power down and lock out the spindle before inserting or removing the bit. Insert the shank fully into the collet and tighten to the router or spindle manufacturer's specified collet torque procedure. Verify spindle speed and feed rate settings are appropriate for the material being routed before beginning the cut.