OSG Screw Thread Insert STI Tap: Spiral Fute, 1/2"-20 UNF, H4 / 2B-3B

An OSG spiral-flute STI tap is used to cut internal threads in aluminum for screw thread inserts. It is designed for through-hole applications, with spiral flutes that evacuate chips upward, preventing clogging and ensuring clean threads in softer materials like aluminum.

The OSG STI tap has a 1/2"-20 UNF thread size, H4 / 2B-3B tolerance, and 2 flutes. It is a spiral-flute design for aluminum, with manufacturer part number 1303901308. The H4 tolerance ensures proper fit for STI inserts, while 2B-3B covers standard and close-fit thread classes.

You can source OSG STI 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 1303901308 spiral-flute tap.

Select an OSG STI tap with spiral flutes for aluminum to ensure chip evacuation in through holes. Match the tap thread size (e.g., 1/2"-20 UNF) to your insert and use H4 tolerance for standard insert fit. For aluminum, avoid plug or bottoming taps unless specified for blind holes.