OSG Screw Thread Insert STI Tap: Spiral Fute, 7/8"-14 UNF, H4 / 2B-3B, 4 Flute

The OSG 0148301 is a spiral-flute STI tap designed for threading holes in steel and stainless steel before installing screw thread inserts. Its bottoming chamfer allows threading close to the bottom of blind holes, making it ideal for repair and production work in automotive, aerospace, and general manufacturing.

This OSG tap has a thread size of 7/8"-14 UNF, with a ground thread tolerance of H4 for the tap and 2B-3B for the mating insert thread. It features 4 flutes, a spiral-flute design for chip evacuation, and a bottoming chamfer. The manufacturer part number is 0148301.

3G Electric supplies OSG taps like the 0148301 to customers worldwide. 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 cutting tools to any country.

Select an STI tap that matches the insert's thread size and class. For a 7/8"-14 UNF insert requiring a 2B-3B fit, use a tap with H4 tolerance like this OSG model. Ensure the tap has the correct chamfer type—bottoming for blind holes, plug for through holes—and consider material-specific coatings for steel or stainless steel.