OSG Screw Thread Insert STI Tap: Spiral Fute, 7/8"-9 UNC, H5 / 2B-3B, 4 Flute

An OSG spiral-flute STI tap is used to cut internal threads for screw thread inserts in materials that produce stringy chips, such as aluminum or steel. The spiral-flute design evacuates chips upward, making it ideal for blind-hole applications. This tap creates threads that accept helical coil inserts for stronger fastening in softer materials.

This OSG STI tap has a UNC thread size of 7/8"-9, with an H5 / 2B-3B tolerance class and a bottoming chamfer. It features 4 spiral flutes for chip evacuation. The manufacturer part number is 10802100. It is designed for use with screw thread inserts and is suitable for blind-hole threading in various materials.

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 times. 3G Electric supplies genuine OSG cutting tools, including the 7/8"-9 UNC spiral-flute tap, to customers across multiple industries.

To select the correct OSG STI tap, match the tap's thread size and pitch to the insert's internal thread specification. For a 7/8"-9 UNC insert, use the corresponding STI tap with a bottoming chamfer for blind holes. Ensure the tap tolerance (H5) aligns with the required thread class (2B-3B). Always verify the material and flute style for chip evacuation.