Onsrud 40-131 Upcut Spiral Router Bit 3/8 in Dia

Product Description

The ONSRUD 40-131 is a double-edge upcut spiral router bit designed for milling block and plate aluminum as well as natural wood. Built from high speed steel with no coating, it measures 0.375 inches in cutting diameter with a 1-inch length of cut and a 3-inch overall length. The upcut flute geometry pulls chips upward and away from the workpiece, helping maintain a clean cutting zone and reducing heat buildup at the tip. The right-hand cutting direction and 19 to 32 degree helix angle make it well suited for through-cuts and plunge operations where chip evacuation is critical. Shank diameter is 3/8 inches with a 2-inch shank length, providing solid tool holder engagement.

This bit is intended for CNC router applications in fabrication shops and woodworking facilities handling aluminum plate, aluminum block stock, and natural wood. The double-edge design delivers balanced cutting forces, which helps extend tool life in production environments. It fits standard 3/8-inch collets and is commonly used in both light industrial and professional shop settings where consistent chip clearance and surface finish are priorities.

Key Features

• Upcut flute geometry evacuates chips away from the cut for cleaner results
• Double-edge design provides balanced cutting forces and improved tool life
• High speed steel construction handles aluminum and natural wood applications
• 19 to 32 degree helix angle supports efficient chip flow in through-cut operations
• Uncoated finish - no coating buildup risk when cutting non-ferrous materials
• 2-inch shank length offers secure collet engagement and reduced runout

Compatibility

Designed for use in CNC routers equipped with 3/8-inch collets. Rated for block and plate aluminum and natural wood applications. Part of the ONSRUD 40-100 series.

Installation Notes

Installation should be performed by a qualified CNC machinist or tooling technician with the spindle fully powered down and locked out before changing tooling. Insert the shank fully into a clean, undamaged 3/8-inch collet and tighten to the router manufacturer's specified torque range. Inspect the cutting edges for chips or wear before each run. When routing aluminum, verify feed rate and spindle speed settings match the material and bit diameter to prevent welding of aluminum chips to the cutting edge.