Onsrud 91-106 Spoilboard Surface Insert Cutter 4in

Product Description

The ONSRUD 91-106 is an indexable spoilboard surface insert cutter designed for CNC routing applications requiring precise, repeatable surfacing passes. Built around a 4-inch cutting diameter and a 3/4-inch shank, this tool accepts three carbide inserts of the ICK L 142 style, secured by screw-holding method for positive retention during high-feed operation. The right-hand cut geometry and straight cutter type make it a reliable choice for flattening MDF, phenolic, plywood, and other spoilboard materials on flatbed CNC routers. Licensed CNC machinists and production woodworking shops are the primary installers. Overall length is 3.05 inches with a 2-1/4-inch shank length, and maximum depth of cut is 1/8 inch per pass.

This cutter is suited for surfacing operations on aluminum, plastic, and wood workpieces. Its primary application is resurfacing CNC router spoilboards to restore a flat, true reference plane, though it also performs well on shallow facing passes on flat stock. The 4-inch diameter covers a wide swath per pass, reducing total cycle time when surfacing large panels. The indexable insert design allows worn cutting edges to be rotated or replaced without pulling the body from the spindle, which keeps downtime low in production environments.

Key Features

• 4-inch cutting diameter for wide coverage per surfacing pass
• Accepts 3 ICK L 142 style carbide inserts, screw-held for secure retention
• Straight cut geometry with right-hand cutting direction
• Maximum depth of cut: 1/8 inch per pass
• Compatible workpiece materials: aluminum, plastic, and wood
• Indexable inserts reduce downtime - rotate or replace edges without removing the body

Compatibility

Designed for use with ICK L 142 style inserts (compatible insert size code 142). Fits CNC router spindles with a 3/4-inch collet or tool holder. Intended for spoilboard surfacing and shallow facing operations on aluminum, plastic, and wood.

Installation Notes

Installation should be performed by a qualified CNC machinist or tooling technician. Power down and lock out the machine spindle before seating or indexing inserts. Verify collet torque and runout with a dial indicator before production use. Follow the router manufacturer's recommended RPM range for the cutter diameter to avoid overloading the spindle or damaging the inserts.