Osg 1430902 Spiral Flute Tap 3/8-16 Unc Bottoming Hss

Product Description

The OSG 1430902 is a spiral flute bottoming tap designed for cutting 3/8-16 UNC internal threads in a range of ferrous and non-ferrous materials. It is manufactured from high-speed steel and carries an elektraLUBE coating that reduces friction during cutting and extends tool life in production tapping operations. The 50-degree helix angle drives chips up and out of the flute, making this tap well suited to blind-hole applications where chip evacuation is critical. With a 3B class of fit and H3 thread limit, it produces threads within standard tolerance ranges required by most mechanical assemblies. The overall length is 2-15/16 inches and shank diameter is 0.429 inches.

This tap is used in machine shop, maintenance, and production environments where blind-hole tapping is performed. The bottoming chamfer allows threading to the bottom of a hole with minimal unthreaded length, a common requirement in close-tolerance fixture, structural, and mechanical component work. Compatible materials include aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel, covering a broad range of typical shop applications. It is appropriate for use in CNC machining centers, manual drill presses, and tapping arms where right-hand spiral flute taps in the UNC thread family are specified.

Key Features

• Bottoming chamfer for threading to the bottom of blind holes
• 50-degree helix angle promotes upward chip evacuation in blind-hole applications
• elektraLUBE coating reduces friction and improves tool life
• High-speed steel construction for use across a wide range of workpiece materials
• H3 thread limit with 3B class of fit for standard tolerance internal threads
• Right-hand flute and right-hand thread direction, Series 107

Compatibility

Designed for tapping 3/8-16 UNC threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. No coolant-through capability; suited for external cutting fluid application.

Installation Notes

Installation of taps should be performed by a qualified machinist or maintenance technician. Secure the workpiece fully before tapping and ensure the tap is aligned perpendicular to the hole to avoid thread damage or tap breakage. Apply appropriate cutting fluid to the tap and workpiece for the material being threaded. Power down and de-energize any machine spindle before loading or removing the tap from the holder.