OSG UNF Spiral Flute Threading Tap in No. 6 x 40 is a precision threading tool designed for blind-hole applications, ideal for machinists who need dependable, accurate internal threads. Built to deliver consistent results in metalworking projects, it blends durability with efficient chip evacuation for everyday and critical tasks.

• Thread type: UNF (Unified National Fine) thread for precise, tight internal threads in metal.
• Flute design: Spiral flute geometry optimizes chip evacuation in blind holes, reducing binding and prolonging tool life.
• Material: HSS-E (high-speed steel with cobalt) provides higher hardness and heat resistance for demanding cuts.
• Coating: Steam oxide coating offers improved wear resistance and lubricity, helping extend tap life in tough materials.
• Size: No. 6 x 40 — standard imperial size suitable for common UNF applications.
• Application: Specifically engineered for blind-hole internal threads in steel and alloy parts, delivering clean, accurate threads every time.
• Brand: OSG — a trusted name in precision threading tools.

With its robust HSS-E composition and spiral-flute geometry, this tap produces true, consistent threads while efficiently removing chips from blind holes. The cobalt enhancement and steam-oxide coating help resist heat and wear, enabling longer tool life and fewer reworks in challenging materials. Whether you’re threading a motor housing, valve body, or machinery component, this tap provides reliable performance, reduces tapping torque, and delivers smooth, accurate threads that pair beautifully with standard UNF fasteners.