Osg 1626003508 Thread Forming Sti Tap 1/2-13 Unc H5

Product Description

The OSG 1626003508 is a thread forming STI tap designed for cutting 1/2-13 UNC internal threads in a wide range of metals. Thread forming taps displace material rather than cutting chips, producing stronger threads with no swarf to clear. This tap is ground to an H5 thread limit with a semi-bottoming chamfer, making it suitable for threading holes that approach the bottom without requiring a full bottoming tap. It is manufactured from high-speed steel and carries a V finish. With an overall length of 4.3307 inches and a thread length of 1.8125 inches, it fits standard tap holders used in machining and maintenance environments. Installation is typically performed by machinists, tool and die specialists, or maintenance mechanics.

This tap is intended for use on through-holes and semi-blind holes requiring 1/2-13 UNC thread profiles per Class 3B fit tolerances. Its material compatibility range includes carbon steel, alloy steel, stainless steel, aluminum, nickel, hardened steel, and titanium alloy, making it a versatile choice across production and repair applications. The semi-bottoming chamfer provides 3 to 5 thread lead-in, offering a balance between bottoming capability and ease of starting. It is part of the OSG Series 16260 STI tap line.

Key Features

• Thread forming design displaces material to produce stronger threads without chip generation
• H5 thread limit ground for Class 3B fit tolerance on 1/2-13 UNC threads
• Semi-bottoming chamfer for use in semi-blind and near-bottom hole applications
• High-speed steel construction suitable for a broad range of workpiece materials including stainless steel, titanium alloy, and hardened steel
• V finish for general-purpose tapping performance
• STI tap profile produces threads sized for STI helical coil thread inserts

Compatibility

Designed for use with standard STI tap holders accepting a 0.48-inch shank diameter and 0.36-inch square drive. Compatible with carbon steel, alloy steel, stainless steel, aluminum, nickel, hardened steel, and titanium alloy workpieces. Produces 1/2-13 UNC STI threads for helical coil insert installation.

Installation Notes

This tap is installed and operated by machinists or maintenance mechanics using a standard tap wrench, tapping head, or CNC spindle configured for the appropriate feed rate. Always ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct STI tap drill diameter before tapping. Use cutting fluid appropriate for the workpiece material to extend tool life and improve thread finish. Power down or de-energize any machine before changing tooling.