OSG Screw Thread Insert STI Tap: Spiral Fute, 1/4"-20 UNC, H3 / 2B-3B

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

The OSG STI tap has a thread size of 1/4"-20 UNC, with a thread tolerance of H3 / 2B-3B. It features a spiral flute design with 2 flutes, optimized for chip evacuation in aluminum. The manufacturer part number is 1303900608, and it is classified as a spiral-flute STI tap for thread insert installation.

3G Electric supplies OSG STI taps worldwide, including the 1/4"-20 UNC model 1303900608. As a global industrial distributor, we handle full logistics, customs clearance, and delivery to your location. Contact us for availability and lead time; we source and deliver OSG tooling to any country.

Select an STI tap with the same thread size and pitch as the insert you will install. For aluminum, choose a spiral-flute design like this OSG tap for efficient chip removal. Verify the thread tolerance (H3 / 2B-3B) matches your required fit class. Always use appropriate cutting fluid for aluminum to extend tool life.