The OSG UNC Spiral Flute Threading Tap is built for precise, reliable threading in blind holes, making it ideal for machinists and fabricators who demand consistent results in metalwork.

• Size: No. 4 UNC x 40 — standard coarse-thread tap sized for small fastener work in blind holes.
• Material: HSS‑E (high‑speed steel with cobalt) for exceptional hardness, wear resistance, and hot hardness in demanding cutting conditions.
• Coating: Steam Oxide coating to reduce friction, improve wear resistance, and extend tool life during repetitive tapping.
• Flute Design: Spiral flutes facilitate efficient chip evacuation in blind holes, helping prevent clogging and tool breakage.
• Thread Type: UNC (coarse) threading standard to match common fasteners and ease of assembly in a variety of metals.
• Application: Specifically optimized for blind-hole threading in metal components, delivering clean, accurate internal threads with fewer passes.
• Brand: OSG — trusted by professionals for precision threading tools and long-term performance.

This tap delivers reliable, precise threads with a focus on durability and efficiency. The combination of cobalt-enhanced steel and Steam Oxide coating supports sustained performance under heat and load, while the spiral flute design minimizes chip buildup in blind holes. Whether you’re assembling small mechanical components or refining items with tight internal tolerances, this tap helps you achieve strong, consistent threads and longer tool life.