Osg 1715908 Spiral Flute Sti Tap 6-32 Unc 3 Flute

Product Description

The OSG 1715908 is a spiral flute STI tap designed for cutting 6-32 UNC threads in insert-ready applications. Built from powdered metal with a V coating, this tap features a 45-degree helix angle and a semi-bottoming chamfer that allows threading close to the base of a blind hole. It carries a 3B class of fit, making it suitable for standard-tolerance threaded insert work. With an overall length of 2.375 inches and a shank diameter of 0.194 inches, it fits standard tap holders used in machine shop and production environments. Licensed machinists and tooling technicians install this tap in CNC machining centers, drill presses, and manual tapping setups.

This tap is built for STI (Screw Thread Insert) applications where a thread must be cut oversize to accept a helical insert such as a wire thread insert. The 6-32 UNC thread form, three right-hand flutes, and 0.311-inch thread length make it well suited for shallow-to-moderate depth tapping in metals including aluminum, steel, and similar machinable alloys. It is appropriate for both production runs and repair work where stripped or damaged threads need to be restored using an insert system.

Key Features

• 6-32 UNC STI thread form for use with helical wire thread inserts
• 45-degree helix angle promotes chip evacuation in blind hole applications
• Semi-bottoming chamfer allows threading closer to hole bottom than a standard taper chamfer
• Powdered metal construction offers improved wear resistance over standard HSS
• V coating reduces friction and extends tool life in general-purpose tapping
• 3B class of fit delivers standard tolerance thread geometry for insert compatibility

Compatibility

Designed for use in STI tapping applications requiring a 6-32 UNC oversize thread to accept a helical wire thread insert. Compatible with standard tap holders and collet chucks sized for a 0.194-inch shank diameter.

Installation Notes

This tap should be installed by a qualified machinist or tooling technician familiar with STI thread systems. Ensure the workpiece is securely fixtured and the spindle speed and feed rate are appropriate for the workpiece material before tapping. Apply cutting fluid rated for the material being tapped to reduce heat and improve thread finish. Never reverse the tap under power without confirming the machine and tap holder are configured for thread-cutting reversal.