OSG Threading Tap - UNF Spiral Point HSS-E - Steam Oxide Coated - Through Hole - 5/8 x 18OSG UNF Spiral Point Threading Tap, 5 8 x 18 UNF, is engineered for precise through hole tapping with durability you can trust. Crafted from HSS E (high speed steel with cobalt) and finished with a Steam Oxide coating, its built to handle demanding machining tasks while delivering clean, accurate threads. Thread size and standard: 5 8 18 UNF threading for through hole applications, designed to meet exacting thread requirements. Material: HSS E (high