Norton Wire Cup Brush With Protective Guard, Threaded Hole, Carbon Steel, Partial Twist Knotted, 4" Diameter, 0.02" Wire Diameter, 5/8"-11 Arbor, 9000 rpm (Pack of 1) Single row, twist knot construction Limits flaring of the brush on corners and angles Rigid structure; high impact cutting and cleaning on more demanding applications Available with plastic guard; application-specific Protective guard opens up into a shield~