OSG Screw Thread Insert STI Tap: Spiral Fute, 5/8"-18 UNF, H4 / 2B-3B

An OSG spiral-flute STI tap is used to cut internal threads in steel and stainless steel for screw thread inserts. The spiral-flute design evacuates chips upward, making it ideal for blind-hole applications. This tap produces threads that accept STI (screw thread insert) fasteners, commonly used in aerospace, automotive, and industrial maintenance.

The OSG 30204201 is a spiral-flute STI tap with thread size 5/8"-18 UNF, ground thread tolerance H4 / 2B-3B, and 4 flutes. It is designed for threading steel and stainless steel. The H4 tolerance ensures proper fit for STI inserts, while the 2B-3B class covers both standard and tighter internal thread requirements.

You can source OSG taps worldwide through 3G Electric, a global industrial equipment distributor. We handle full logistics, customs clearance, and delivery to your location. Contact us for availability and lead time on the OSG 30204201 spiral-flute STI tap. We supply genuine OSG tooling for manufacturing and maintenance operations.

Select an OSG STI tap based on thread size, material, and hole type. For steel and stainless steel, use a spiral-flute tap like the 30204201 for blind holes. Ensure the tap tolerance (e.g., H4 / 2B-3B) matches the insert and thread class required. Always use proper cutting fluid and follow OSG's recommended speeds and feeds for best thread quality.