Onsrud 57-365 Downcut Spiral Router Bit 0.5 in Dia

Product Description

The ONSRUD 57-365 is a downcut spiral router bit machined from solid carbide for use in CNC routing and handheld router applications. It features a 0.5-inch cutting diameter, a 1.625-inch length of cut, and a 30-degree helix angle with a right-hand cutting direction. The downcut flute geometry directs chips upward into the cut, which helps hold the top surface of workpieces against the spoilboard and minimizes surface tearout on the face side. At 0.27 pounds, the bit is designed for fast tool changes in production environments where surface finish quality is critical.

This bit is suited for routing natural wood, solid surface materials, and wood composites in both shop and field applications. The double-edge configuration and solid carbide construction support consistent performance across repeated passes in production woodworking, cabinet fabrication, and countertop work. The 1/2-inch shank diameter fits standard 1/2-inch collets on CNC routers and production-grade handheld routers. The 1-7/8-inch shank length provides secure collet engagement, reducing runout during high-feed-rate passes.

Key Features

• Downcut flute geometry reduces top-face tearout on laminates and veneered panels
• Solid carbide construction for extended tool life in abrasive wood composite materials
• 30-degree helix angle balances chip evacuation with edge stability
• Right-hand cutting direction compatible with standard CNC router spindle rotation
• Double-edge design for smooth finish passes in natural wood and solid surfaces
• Uncoated carbide substrate suitable for natural wood, MDF, and solid surface without coating buildup concerns

Compatibility

Designed for use with materials including natural wood, solid surfaces, and wood composites. Fits any router or CNC spindle accepting a 1/2-inch shank collet. Part of the ONSRUD 57-200 series.

Installation Notes

This bit should be installed and changed by a qualified machinist or CNC operator following the router or spindle manufacturer's collet torque and runout specifications. Ensure the router is fully powered down and the spindle has come to a complete stop before changing tooling. Inspect the collet and collet nut for wear before seating the shank, and verify the shank is inserted to the recommended depth to avoid chatter. Feed rate and spindle speed should be set per the material being cut and the manufacturer's recommended chip load parameters for carbide spiral bits.