Ultimax-Coated Version
The UM suffix identifies the Ultimax-coated version of the verified the uncoated base size downcut spiral size.


Ultimax-coated solid-carbide downcut spiral router bit designed for clean routing in solid wood, wood composites, laminated materials, and selected plastics. Its 3/8-inch cutting diameter, 1-inch cutting edge, matching 3/8-inch shank, right-hand rotation, and 3-inch overall length support dados, grooves, profiles, panel routing, and production machining where top-edge finish matters.
This production tool combines solid-carbide construction, two downcut spiral flutes, Ultimax coating, right-hand rotation, and a matching 3/8-inch shank for controlled routing where clean entry-side edges are important.
Designed for compatible CNC routers and routing equipment using a precision 3/8-inch collet or approved toolholding assembly with right-hand spindle rotation.
The Royce Ayr 2-Flute Ultimax Downcut Spiral Router Bit R57-32222UM is designed for clean routing in solid wood, wood composites, laminated materials, and selected plastics. Its downcut geometry directs cutting pressure toward the workpiece, helping support the top edge during dados, grooves, profiles, and general routing where entry-side finish is important.
The 0.3750-inch cutting diameter, 1.000-inch cutting edge, matching 0.375-inch shank, and 3.000-inch overall length provide a balanced 3/8-inch production format for compatible router and CNC router systems. The UM suffix identifies this SKU as the Ultimax-coated version of the the uncoated base size size.
This HC solid-carbide tool uses two downcut spiral flutes, Ultimax coating, and right-hand rotation. Correct collet condition, minimum practical projection, verified runout, suitable RPM, feed rate, depth-per-pass, workholding, and chip or dust evacuation are essential for maintaining finish quality, heat control, dimensional accuracy, and reliable tool life.
Technical Specifications
The UM suffix identifies the Ultimax-coated version of the verified the uncoated base size downcut spiral size.
The downcut spiral directs cutting pressure toward the workpiece to help support the entry-side edge during routing.
The matching diameter and shank, 1-inch cutting edge, RH rotation, and 3-inch overall length define a balanced production configuration.
Confirm that the spindle, collet, and toolholder accept an exact 3/8-inch (9.53 mm) shank, support right-hand rotation, and provide adequate clearance for the 3-inch overall length and required projection. Inspect and clean the collet, minimize unsupported projection, verify runout, and match spindle speed, feed rate, cut depth, workholding, guarding, and chip or dust evacuation to the selected material. Because this is a downcut tool, confirm chip-flow and pass strategy before deeper grooves or plastic routing.
The Royce Ayr 2-Flute Ultimax Downcut Spiral Router Bit R57-32222UM provides an Ultimax-coated HC solid-carbide solution for clean routing in solid wood, wood composites, laminated materials, and selected plastics.
Its 3/8-inch cutting diameter, 1-inch cutting edge, matching shank, two-flute downcut geometry, right-hand rotation, and 3-inch overall length support controlled production machining when correctly held and operated.