Made in the USA, Spearhead high speed steel burs are known for their hardness and durability. Hand crafted from superior M2 steel, they stay sharper and last up to 10 times longer than standard tungsten vanadium steel. Spearhead burs feature a special spiral cut which cuts faster with less heat buildup and reduces "clogging". All have 3/32" (2.35mm) shanks and a rockwell hardness of 63-65. Sizes range from 1-34 (0.90-11.00mm).