OSG Screw Thread Insert STI Tap: Spiral Fute, 5/8"-11 UNC, H4 / 2B-3B, 4 Flute

An OSG Screw Thread Insert STI Tap cuts internal threads in steel and stainless steel for installing helical wire thread inserts. It is commonly used in aerospace, automotive, and heavy equipment repair where stripped threads must be restored to original strength without replacing the parent component.

The OSG 30203901 is a spiral-flute STI tap with 5/8"-11 UNC thread, H4 / 2B-3B tolerance, 4 flutes, and a bottoming chamfer. It is designed for threading holes in steel and stainless steel before inserting screw thread inserts. The H4 pitch diameter tolerance ensures a precise fit for the insert.

3G Electric supplies OSG STI Taps like the 30203901 to customers worldwide. We handle full logistics, customs clearance, and delivery to your facility. As a global industrial sourcing partner, we provide genuine OSG cutting tools for maintenance and production needs across 14 industrial departments.

Select an STI tap that matches the original thread size and pitch, such as 5/8"-11 UNC. The tap must be marked for screw thread inserts (STI) and have the correct tolerance class (e.g., H4 / 2B-3B). Use a bottoming chamfer for blind holes and a spiral-flute design for chip evacuation in steel and stainless steel.