This RedLine Tools 4-Flute Variable Index and Helix Square End Mill (REP4066) is a precision cutting tool made in the USA from high-quality carbide. Featuring a 0.31-inch cutting diameter with a matching 0.31-inch shank, this square end mill is designed for superior performance in machining applications. The variable helix and variable index design reduces chatter and improves cutting stability, while the premium AlTiSN finish enhances durability and heat resistance. With its compact dimensions (2 inches in length and 0.44 inches in width) and lightweight construction (10 grams), this end mill offers excellent maneuverability and control. The 4-flute configuration provides an optimal balance between material removal rate and surface finish quality. Each unit comes individually packaged, weighing just 0.25 pounds, making this tool an essential addition to any professional machinist's toolkit.