Picatinny Rail or "Pic Rail" cutters, Pic Rail Groove cutters and Attachment/Accessory cutters designed to MIL-STD-1913 specs with extra "Secret Squirrel Sh*t" performance enhancements. Gorilla Mill patented geometries makes milling the entire Pic Rail in a single pass easy peasy. Solid carbide high performance 3, 4, and 5 flute cutters manufactured right here in 'Merica by "We The People". GMS2 coated for high heat resistance, longer tool life and faster running speeds. Run all of the Gorilla Arsenal cutters with cocky-ass confidence in ferrous and non-ferrous materials. Run them in 6061, 7051, 300, 400 and PH series stainless, titanium, high temp alloys, high carbon steel, low carbon steel, somewhere in between carbon steel, rice pudding, concrete and a bowl of Lucky Charms® or lava! We don't give two sh*ts what you run them in. JUST RUN THEM HARD!