OSG Screw Thread Insert STI Tap: Spiral Fute, #4-40 UNC, H2 / 2B-3B

This OSG spiral-flute STI tap is designed for cutting internal threads in aluminum and non-ferrous materials before installing screw thread inserts. It is commonly used in aerospace, automotive, and general manufacturing applications where strong, wear-resistant threads are required in softer base materials.

The OSG STI tap (MPN 1303900208) has a #4-40 UNC thread size, H2 / 2B-3B tolerance, and a 2-flute spiral-flute design optimized for aluminum. It is a spiral-flute STI tap that produces threads to accept standard screw thread inserts. The H2 limit ensures precise thread fit for insert installation.

3G Electric supplies OSG STI taps worldwide, including the #4-40 UNC spiral-flute model. As a global industrial equipment distributor since 1990, we handle full logistics, customs clearance, and delivery to your site. Contact us for availability and lead time on this and other OSG tooling.

Select an OSG STI tap with spiral flutes for aluminum to ensure efficient chip evacuation and reduced cutting torque. Match the tap thread size (e.g., #4-40 UNC) and tolerance (H2 / 2B-3B) to your insert requirements. Use proper cutting fluid and maintain recommended speeds for best thread quality and tool life.