Osg 8005700 Spiral Flute Sti Tap 6-32 Unc Hss

Product Description

The OSG 8005700 is a spiral flute STI (Screw Thread Insert) tap designed for cutting 6-32 UNC threads in a variety of metals. Built from high-speed steel with a bright finish, this tap features a 50-degree helix angle and a bottoming chamfer, making it well-suited for threading holes close to the bottom of blind bores. With 3 flutes and a right-hand flute direction, it evacuates chips efficiently during the tapping operation. Overall length is 2 inches, shank diameter is 0.194 inches, and thread length is 0.314 inches (11/16 inches). Machinists, tool-and-die makers, and maintenance technicians use this tap where STI inserts are required to restore or create strong threaded connections.

This tap is intended for use in materials including aluminum, carbon steel, cast iron, and hardened steel. The 6-32 UNC thread size is commonly encountered in light fastening applications across electronics, machine components, and sheet metal assemblies. The bottoming chamfer allows threading to be completed as close to the bottom of a blind hole as possible, which is a frequent requirement in precision machining and repair work. It carries a Thread Limit designation of H3, appropriate for standard STI insert fits in these materials.

Key Features

• 6-32 UNC thread form with STI geometry for use with screw thread inserts
• 50-degree helix angle promotes efficient chip evacuation in blind holes
• Bottoming chamfer enables threading to the full depth of blind bores
• High-speed steel construction handles aluminum, carbon steel, cast iron, and hardened steel
• Bright finish with H3 thread limit for consistent fit with standard STI inserts
• Right-hand flute direction, 3 flutes, Series S108

Compatibility

Designed for use with 6-32 UNC screw thread inserts in applications requiring STI-style tapped holes across aluminum, carbon steel, cast iron, and hardened steel workpieces.

Installation Notes

Tapping operations should be performed by qualified machinists or maintenance technicians using a properly aligned tap handle, tapping head, or CNC machine set for right-hand rotation. Ensure the workpiece is securely fixtured and that appropriate cutting fluid is applied for the material being tapped. For blind holes, use a bottoming tap sequence and clear chips frequently to prevent tap breakage. Follow shop safety practices and applicable standards when working with rotating tooling.