High Speed Steel Burs Last Longer, Stay Sharper! These Spearhead brand High Speed Steel bur are expertly crafted in the USA. High Speed Steel (HSS) is a high carbon alloy of steel. These burs are made of an alloy called M2 High Speed Steel that contain tungsten, molybdenum, chromium and vanadium. The alloy is heat-treated during manufacture to a hardness of HRC 63-65. This steel is more abrasion resistant and can with stand the high temperature generated from cutting without losing its hardness. This means these burs can cut faster than the lesser expensive carbon steel and tungsten/vanadium burs. The HSS burs, if used properly, have a much longer life.
That doesn't mean you can't forget to use bur lubricant. Bur lube reduces friction which not only reduces heat, but cuts down on chatter. These High Speed burs also feature standard 3/32" (2.35mm) shanks, and as a trademark of the Spearhead brand, each shank is stamped with the bur's size number. HSS burs are used on precious and semi-precious metals such as gold, silver, copper, brass, aluminum, niobium, pewter and more.
The main use of setting burs is cutting seats in tube, bezel and prong settings. The sides of the setting bur are straight, unlike the hart (bearing) bur so it it is less likely to cut too deep. With the setting bur though, it is important to choose the exact size to match the stone size you are setting. The setting bur allows you to cut a seat a the perfect angle for symmetrical stones.
This Setting bur set contains 1 each of 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2.1mm, 2.3mm, 2.5mm, 2.7mm, 2.9mm, 3.1mm, 3.3mm, 3.5mm, 3.8mm, 4.0mm, 4.3mm, 4.5mm, 4.7mm, 5.0mm, 5.2mm, 5.4mm, 5.6mm, 5.9mm, 6.3mm, 6.7mm, 7.2mm, 7.6mm, 8.0mm, 8.9mm, 9.6mm, 10.4mm, 11.1mm and a bur storage box.