Osg 1212805 Spiral Point Tap 8-32 Unc Tin Hss

Product Description

The OSG 1212805 is a spiral point tap designed for cutting 8-32 UNC internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel (HSS) with a titanium nitride (TiN) coating, it delivers extended tool life and reduced friction during threading operations. The plug chamfer provides a gradual lead-in, making it well suited for through-hole applications. With 2 flutes and an H3 thread limit, it produces Class 2B fit threads that meet standard fastener assembly tolerances. Overall length is 2.125 inches with a shank diameter of 0.168 inches and a thread length of 0.39 inches.

This tap is used in machine shop, maintenance, and field repair applications where 8-32 UNC threads are required in through-hole configurations. It is appropriate for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. The TiN coating makes it a practical choice when tapping abrasive or harder materials where uncoated HSS would wear more rapidly. Machinists, tool-and-die technicians, and maintenance mechanics commonly specify this tap for production and repair work on threaded fastener holes.

Key Features

• 8-32 UNC thread form with H3 thread limit for consistent Class 2B fit
• TiN coating reduces friction and extends tool life compared to uncoated HSS
• Plug chamfer suits through-hole threading applications
• Right-hand thread direction, compatible with standard tapping equipment
• 2-flute spiral point design pushes chips forward ahead of the tap
• No coolant-through requirement simplifies setup on standard equipment

Compatibility

Designed as an OEM-style replacement or direct-use spiral point tap for any application requiring 8-32 UNC, Class 2B, H3 thread limit in through-hole configurations across aluminum, cast iron, and carbon or hardened steel workpieces.

Installation Notes

This tap is installed and driven by licensed machinists or qualified maintenance mechanics using a standard tap handle, tapping head, or CNC machine tool holder. Always ensure the workpiece is securely fixtured and the pilot hole diameter matches the recommended drill size for 8-32 UNC before beginning the threading operation. Apply a suitable cutting fluid for the workpiece material to minimize heat buildup and extend tap life. Do not reverse the tap under power without confirming the machine or handle supports back-out without binding.