Osg 1625538627 Thread Forming Tap 3/8-16 Unc Cobalt

Product Description

The OSG 1625538627 is a thread forming tap designed for right-hand internal threading in a wide range of metals. Unlike cutting taps, thread forming taps cold-form the thread profile by displacing material rather than cutting it, producing stronger threads with no chips to clear. This tap covers the 3/8-16 UNC thread size to a 2B class of fit and features a semi-bottoming chamfer for threading close to the bottom of blind holes. Manufactured from cobalt high-speed steel and finished with a V coating, it is built to handle demanding materials including stainless steel, titanium, high-nickel alloys, and hardened steel. Overall length is 5.9055 inches with a thread length of 0.6260 inches.

This tap is suited for production and maintenance applications across machining, fabrication, and general metalworking environments. The H7 thread limit and 2B class of fit make it appropriate for standard-tolerance fastener applications. Material application data covers aluminum, cast aluminum, carbon steel, alloy steel, die steel, stainless steel, high-nickel alloy, and titanium, giving it broad utility in both job shop and production floor settings. It is installed by machinists and toolroom technicians using a tapping machine, CNC machining center, or manual tap wrench.

Key Features

• Thread forming design displaces material rather than cutting, producing chip-free threads and improved thread strength
• Semi-bottoming chamfer allows threading to within a few pitches of blind hole bottom
• Cobalt HSS construction provides heat and wear resistance for hard and abrasive workpiece materials
• V coating reduces friction and improves tool life in difficult-to-machine alloys
• H7 thread limit and 2B class of fit for standard-tolerance UNC threaded assemblies
• Right-hand thread direction compatible with standard tapping equipment and fixturing

Compatibility

Designed for use in 3/8-16 UNC tapping applications across aluminum, cast aluminum, carbon steel, alloy steel, die steel, stainless steel, high-nickel alloy, and titanium workpieces. Fits standard tap holders sized for a 0.3810-inch shank diameter.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which is larger than the equivalent cutting tap drill size — consult published forming tap drill charts for the correct diameter before drilling. Secure the workpiece and ensure the tapping spindle is aligned perpendicular to the hole to prevent tap breakage. Use a lubricant or cutting fluid appropriate for the workpiece material; sulfurized or chlorinated cutting oils are typical for steel, while aluminum-specific fluids are preferred for aluminum alloys. This tap is intended for use by qualified machinists or toolroom personnel familiar with thread forming processes.