Osg 1626003008 Thread Forming Sti Tap 3/8-24 Unf H6

Product Description

The OSG 1626003008 is a thread forming STI tap designed for producing internal threads in a range of metals without cutting or removing material. Operating on a cold-forming principle, this tap displaces material to generate strong, work-hardened threads. It carries a 3/8-24 UNF thread specification with an H6 thread limit and a semi-bottoming chamfer, making it suitable for threading holes that require thread engagement close to the bottom. Made from high-speed steel and finished with a V coating, it is used by machinists and maintenance professionals in production and repair applications.

This tap is intended for use on carbon steel, alloy steel, stainless steel, aluminum, nickel, hardened steel, and titanium alloy workpieces. The semi-bottoming chamfer provides a balance between starting ease and bottom-hole thread reach, making it a practical choice for general tapping operations where full bottoming is not required but near-bottom thread depth is needed. It fits standard tapping chucks and tap holders sized for a 0.323-inch shank diameter.

Key Features

• Thread forming design produces work-hardened threads with no chips generated
• 3/8-24 UNF thread size with H6 thread limit for controlled tolerance fit
• Semi-bottoming chamfer for threading near the bottom of blind holes
• High-speed steel construction for durability across a wide range of workpiece materials
• V finish coating for improved surface performance
• Class of fit 2B for standard internal thread applications

Compatibility

Designed for tapping operations in carbon steel, alloy steel, stainless steel, aluminum, nickel, hardened steel, and titanium alloy. Fits tap holders and tapping attachments accommodating a 0.323-inch round shank with a 0.242-inch square drive.

Installation Notes

Thread forming taps require proper cutting fluid or tapping compound appropriate to the workpiece material — this is especially important for stainless steel and titanium alloy. Ensure the tap is aligned perpendicular to the workpiece before applying torque to avoid tap breakage or thread distortion. Use a torque-limiting tapping attachment when possible. Always follow applicable shop safety procedures and manufacturer guidelines for spindle speed based on material and hole diameter.