Osg 8006900 Spiral Flute Sti Tap 8-32 Unc Hss

Product Description

The OSG 8006900 is a high-speed steel spiral flute STI tap designed for cutting Screw Thread Insert (STI) threads in a range of metallic workpiece materials. It features a 50-degree helix angle that promotes efficient chip evacuation upward through the flute, making it well suited for blind-hole tapping operations. The bottoming chamfer allows the tap to cut threads close to the bottom of a blind hole with minimal runout. The bright finish indicates no coating, which is standard for general-purpose cutting in softer to medium-hardness materials. Three flutes provide a balance between chip capacity and core strength for this thread size.

This tap is rated for use in aluminum, carbon steel, cast iron, and hardened steel, covering the most common materials encountered in production machining, maintenance, and repair environments. The 8-32 UNC thread form targets fine-pitch fastener applications common in light mechanical assemblies, electronic enclosures, and instrumentation work. With an overall length of 2.125 inches and a thread length of 0.75 inches, it fits standard tap chucks and holders used in CNC machining centers, drill presses, and hand tapping operations.

Key Features

• 8-32 UNC thread form for STI insert applications
• 50-degree right-hand spiral flute promotes upward chip evacuation in blind holes
• Bottoming chamfer enables threading close to the bottom of a blind hole
• High-speed steel construction with H2 thread limit for controlled fit tolerance
• Bright finish suitable for use with cutting fluids across multiple material types
• OSG Series S108 design for consistent dimensional accuracy

Compatibility

Rated for material applications including aluminum, carbon steel, cast iron, and hardened steel. Designed as an STI tap for cutting oversized threads to accept Screw Thread Insert (STI) inserts in the 8-32 UNC thread size.

Installation Notes

Installation should be performed by a machinist or qualified technician familiar with tapping operations and appropriate cutting speeds for the workpiece material. Secure the workpiece fully before beginning the tapping operation and use a suitable cutting fluid or lubricant matched to the material being tapped. Verify alignment between the tap and the drilled hole before applying torque to avoid tap breakage. Follow applicable shop safety standards and use proper tap holders to maintain concentricity throughout the cut.