The Patent Pending Accu-Burr Carbide Burnisher is a game changer when it comes to turning precise, consistent, and effective hooks (or burrs) on cabinet scrapers. No burnisher will produce better results with less effort and less skill. Guaranteed. This completely new type of burnisher is a collaboration of Blackburn Tools, Union Manufacturing and Lakeshore Carbide. The heart of the Accu-Burr is a 3/16" diameter x 3” long carbide rod with three precision shaped V-grooves of slightly differing angles (5, 10, and 15) ground in the center of the rod. These grooves create burrs on both sides of any scraper edge in a single pass. The 5 groove makes fine hooks for refining finishes or when working with thin venerers, the 10 groove (most common) makes medium hooks for everyday use and the 15 groove makes heavy hooks for shaping wood or removing finishes. The Accu-Burr will turn a precise and consistent hook on: any imaginable size and shape card scraper, it can turn burrs in concave profiles as tight as 3/32” radius any thickness card scraper from as thin as 0.010” up to 0.100” thick any hardness scraper, even High-Speed Steel versions with a hardness of RC 65 thin and profiled scrapers that are held high in a vise that would normally deflect and pose difficulties with a traditional rod burnisher How to use: Prepare your scraper by filing and honing the edges and faces. Secure your scraper in a vise. Hold your Accu-Burr carbide burnisher perpendicular to the scraper edge and centered on either the fine, medium, or coarse groove (the deepest groove is for the coarse burr). Applying light even downward pressure on the burnisher, draw it firmly and smoothly along the length of the prepared scraper edge (a drop of oil on the burnisher will make this action even smoother). The Accu-Burr is self-centering and will draw out a burr on both sides in a single motion. This burnishing will raise a burr that can be barely felt with your finger; if no burr is felt, repeat as needed, but with increasing force, until a nearly imperceptible burr is formed along the entire length of the scraper. A burr can be refreshed 2-3 times by taking an additional pass or two with the Accu-Burr before the edge will need to be refiled and rehoned.