1/4" x 2-3/8" chain bar for radial arm saw mortiser platte river 1 each 889400 platte river create mortise pockets in large timbers. no router or hand method can match the speed and accuracy of woodworker's supply radial arm saw mortising attachment: in addition to making precise 90° cuts, angled mortises are as easy as using your saw's controls - just as you would to make a miter cut. designed primarily for timber framers, this versatile tool can be used in furniture making as well. guard retracts when it contacts workpiece; adjustable depth gauge for consistent and accurate cuts. 6-7/8" maximum cut depth. 1/4" thick x 2-3/8" wide bar with chain. 2,150 fpm chain speed. 9" square maximum timber size. 1-3/16" radius in bottom cut. 1/2" minimum cut distance from table surface; 4-1/2" maximum. fits dewalt, craftsman and later model delta 10" and 12" radial arm saws. u.s. patent no. 5,413,158.