New Dremel #536 Brass Brush A cup-shaped brush with brass wire bristles. 1/2" wide shank 1/8" Ideal for cleaning and surface-finishing items made from gold, bronze, copper or brass. You can use a brass brush to create a soft, satin or matte finish. It is very effective on flat surfaces. (Brass wire is non-sparking and softer than steel.) - For best results, insert the accessory bit all the way into the tool and then back it out slightly before tightening down. This provides plenty of shank for the collet or chuck to hold onto.- Do not run in excess of 15,000 rpm. Therefore, do not use with a Single-Speed MultiPro Rotary Tool or a Heavy-Duty Flex-Shaft Tool unless you use the #221 Foot Speed Control.- Keep a light touch, letting the tips of the brush do the work. Too much pressure can break the wire bristles.- Before using on a material, allow the tool with brush to run at operating speed for at least one minute to discharge any loose wire bristles. Make sure no one stands in front of or in line with the brush