Pearl Abrasive's 4-inch knot wheel features industrial-grade construction and high-tensile-strength wire designed to resist breakage during use. With a 5/8-11 arbor and a maximum speed of 20,000 RPM, it is suited to bead-scale removal, cleaning weld roots and hot passes, and working in corners. **Warning:** This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.