Set of 12 Helvetica brand vanadium steel cup burs, ranging from 0.9 mm to 2.9 mm in diameter, provided in a plastic stand with clear cover. 3⁄32" shanks. Made in Switzerland.
Cup Burs have cutting flutes on the inside of their cup-shaped heads for rounding wire ends and refining prong tips and rivet heads. Because they tends to clog easily, they should always be used with lubrication.
Vanadium Steel burs are economically priced. They cut precisely when new, but don't retain their sharpness as long as other steel alloys. They're used at low speeds.
3/32" dia. shanks are the jeweler's preferred standard for burs and small rotary tools. They fit the adjustable chucks found on most flexshaft handpieces as well as 3/32" handpiece collets.