PORTER-CABLE PCA4548-5 7" x 1/4" x 5/8-11 Metal Grinding Wheel 5pcs PORTER-CABLE PCA4548-5 7" x 1/4" x 5/8-11 Metal Grinding Wheel 5pcs 7" diameter, grit is C24R 1/4" thick 5/8"-11 arbor The max RPM is 8,700