PFERD power knot wheel brush with stringer bead twist. Stringer bead knot wheel brushes are tightly twisted for low flex, high impact brushing action. Designed for root and hot pass weld cleaning in pipe joining applications. Also for general use where a narrow face, aggressive brush is desired for controlled, confined surface contact area. Root and hot pass weld cleaning, applications requiring most aggressive brushing action. Knot wheel brushes with threaded hubs for fast and easy tool changes. Superior rotational balance reduces operator fatigue and improves tool life. Recommendation for optimal performance, use on angle grinders. 3/16-inches face width. 1-1/8-inches trim length. 56 knots. 5/8"-11 thread size. Corrosion resistant, non-rusting material works well with chemicals and solvents. Features excellent bend recovery with a high level of abrasion and wear resistance. ; Stringer bead style is intended for tough applications, featuring low flex, high impact cleaning. It is most com-monly used in the pipeline industry for removing the bead scale that occurs after the joining of two sections of pipe. Knot diameter for stringer bead brushes is between 3/16" and 5/16". Uses in industries area: automotive, transportation, mining, electronics, aerospace, welding, nuclear, textiles, food services, construction, petrochemical, farming, medical, shipbuilding, fabricating, defense, foundries and plastics.