Osg 0145008 Spiral Flute Sti Tap 6-32 Unc Hss

Product Description

The OSG 0145008 is a spiral flute STI (Screw Thread Insert) tap designed for cutting 6-32 UNC internal threads in preparation for helical coil insert installation. Built from high-speed steel with a V-finish coating, this tap features a 45-degree helix angle that promotes efficient chip evacuation in through and blind hole applications. The bottoming chamfer configuration allows threading close to the bottom of a blind hole, making it well suited for tight-tolerance repair and fabrication work. With 3 flutes and an H3 thread limit, it produces a 2B class of fit thread consistent with standard UNC fastener requirements. Machinists, tool and die technicians, and maintenance professionals use this tap in production and repair environments.

This tap is applied wherever a stripped or damaged 6-32 UNC threaded hole requires restoration using a helical coil insert. Common applications include repair of aluminum housings, electronics enclosures, and light-gauge sheet metal assemblies where thread stripping is frequent. The bottoming chamfer is particularly useful when thread depth is limited and full engagement close to the hole floor is required. The 45-degree helix angle is well matched to softer workpiece materials including aluminum, brass, and mild steel. Series 302 designation identifies this as part of OSG standard STI tap line.

Key Features

• 6-32 UNC thread size with 32 threads per inch and H3 thread limit for 2B class of fit
• 45-degree helix angle promotes upward chip evacuation in blind hole drilling
• Bottoming chamfer allows threading close to the bottom of blind holes
• High-speed steel construction provides durability across a range of workpiece materials
• V-finish coating for improved surface finish and reduced friction during cutting
• Right-hand flute direction, 3 flutes, STI profile for helical coil insert preparation

Compatibility

Designed as an OEM-style STI tap for use with standard 6-32 UNC helical coil thread repair insert systems in production and maintenance applications.

Installation Notes

Installation is performed by qualified machinists or maintenance technicians using a standard tap handle or machine tapping setup. Always ensure the workpiece is securely fixtured and the tap is properly aligned to the drilled hole before applying torque to prevent tap breakage. Use cutting fluid appropriate to the workpiece material to extend tap life and improve thread quality. Follow insert manufacturer specifications for the correct STI tap drill size before tapping.