Onsrud 40-003 Upcut Spiral Router Bit 3/16 in Dia 1/4 in Shank

Product Description

The ONSRUD 40-003 is a single-edge upcut spiral router bit designed for precise material removal in aluminum and natural wood applications. Built from high-speed steel (HSS) with an uncoated finish, it features a 3/16-inch (0.1875 inch) cutter diameter and a 5/8-inch length of cut. The upcut flute geometry pulls chips up and out of the cut, reducing heat buildup and keeping the work path clear. With a right-hand cutting direction and a helix angle ranging from 19 to 32 degrees, this bit delivers clean, consistent cuts in both production and job-site routing setups. A licensed machinist or skilled fabricator typically runs this bit in a CNC router or handheld router table.

This bit is suited for light-duty to medium-duty routing in aluminum stock and solid natural wood. The 1/4-inch shank diameter and 2-1/4-inch shank length make it compatible with standard 1/4-inch router collets. The non-piloted design means the operator controls the cut path, making this a good fit for template-guided or CNC-programmed passes. It is used in woodworking shops, aluminum fabrication, sign-making, and light manufacturing environments where accurate edge quality and efficient chip evacuation are required.

Key Features

• Upcut flute geometry evacuates chips away from the workpiece for cleaner cuts
• High-speed steel construction provides durability across aluminum and natural wood materials
• 3/16-inch cutter diameter with 5/8-inch length of cut for controlled, narrow passes
• Right-hand cutting direction with 19 to 32-degree helix angle for smooth chip flow
• Non-piloted design works with CNC routers or template-guided handheld setups
• Uncoated finish - compatible with standard HSS sharpening and reconditioning

Compatibility

Designed for use in routers and CNC routing machines equipped with a 1/4-inch collet. Rated for aluminum and natural wood material applications per manufacturer specification.

Installation Notes

Always power down and de-energize the router before changing bits. Insert the shank fully into the collet and tighten to the collet manufacturer's torque specification - do not over-tighten or bottom out the shank. Verify spindle speed is appropriate for the cutter diameter and material before starting the cut. Eye protection and hearing protection are standard PPE when operating routing equipment.