Osg 1636000208 Thread Forming Sti Tap M2.5x0.45 Hss

Product Description

The OSG 1636000208 is a thread forming STI tap designed for metric coarse internal threading applications. Unlike cutting taps, this tool cold-forms threads by displacing material rather than cutting chips, producing stronger threads with better surface finish. Built from high-speed steel with a V finish, it carries a D3 thread limit and a 6H class of fit, making it suitable for precision threading in a range of metallic materials. The semi-bottoming chamfer allows threading close to the bottom of blind holes without requiring a fully bottomed chamfer sequence. Overall length is 2.2047 inches, with a 0.141-inch shank diameter and a thread length of 0.625 inches.

This tap is used in machine shop, maintenance, and production environments where M2.5x0.45 metric coarse internal threads are required. Typical applications include tapping blind or through holes in carbon steel, alloy steel, stainless steel, aluminum, nickel, hardened steel, and titanium alloy workpieces. The STI designation indicates compatibility with screw thread inserts, making it appropriate for repair threading and insert installation work. It is suited for use on CNC machining centers, drill presses, and tapping machines where controlled feed and speed can be maintained.

Key Features

• Thread forming design displaces material to create chip-free, stronger threads
• M2.5x0.45 metric coarse thread size with 6H class of fit and D3 thread limit
• Semi-bottoming chamfer for threading close to the base of blind holes
• High-speed steel construction with V finish for wear resistance in varied metals
• STI configuration supports screw thread insert installation and thread repair
• Rated for use in carbon steel, alloy steel, stainless steel, aluminum, nickel, hardened steel, and titanium alloy

Compatibility

Designed for tapping M2.5x0.45 metric coarse threaded holes to accept screw thread inserts in carbon steel, alloy steel, stainless steel, aluminum, nickel, hardened steel, and titanium alloy workpieces.

Installation Notes

Installation is performed by machinists or tooling technicians using a tapping machine, CNC machining center, or hand tap wrench. Ensure the workpiece is securely fixtured and the correct tap drill size for the M2.5x0.45 STI thread form is used prior to tapping. Apply appropriate tapping fluid or cutting oil for the workpiece material to extend tool life and maintain thread quality. Do not exceed the recommended feed rate for the spindle speed being used, as thread forming taps require adequate lubrication and controlled torque to avoid tap breakage.