The MICRO 100 ARMM-120-3S metric size, ZrN - Zirconium Nitride coated, 3 flute, 45? helix, center cutting end mill. Designed and engineered with a "Stealth" cutter-profile. These high performance end mills feature a 45? helix and are excellent for high speed cutting applications in most non-ferrous materials. The special flute geometry provides an extremely smooth and silent cutting action resulting in an exceptional surface finish. Manufactured with close tolerances to ensure ultimate precision and performance. ZrN coatings provide better tool performance over uncoated carbide for numerous non-ferrous type materials. Characteristics include a high hardness with lubricity and resistance. Generally, ZrN coating provides a less expensive alternative to diamond type coatings. Applicable with oxidation temperatures up to 593? C or 1100? F. ZrN coatings are best suited for abrasive non-ferrous alloys, brass, bronze, copper, and most types of aluminums. MICRO 100 Solid Carbide Tools feature more than just a micro-grain of excellent quality. Their substrate is in class of its own resulting from exclusive treating processes that allow increased speed and feed rates. For over 45 years, MICRO 100 is a known industry leader and internationally acclaimed when it comes to solid carbide tooling.