Osg 1733005 Spiral Flute Tap 3/8-16 Unc Tin Vanadium Hss

Product Description

The OSG 1733005 is a spiral flute tap designed for cutting internal 3/8-16 UNC right-hand threads in ferrous and stainless steel workpieces. Built from vanadium high-speed steel with a titanium nitride (TiN) coating, the tap delivers extended wear life and reduced friction during the threading operation. The 45-degree helix angle pulls chips up and out of the hole, making this design well-suited for blind-hole applications. With a modified bottoming chamfer, the tap can thread close to the bottom of a hole while maintaining thread quality. The 3B class of fit meets standard tolerance requirements for general mechanical assemblies. Licensed machinists, toolmakers, and maintenance technicians are the primary users of this tool.

This tap is intended for use in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. It is appropriate for CNC machining centers, drill presses, and hand-tapping operations where chip evacuation is critical. The modified bottoming chamfer and spiral flute geometry make it a practical choice for production tapping of blind holes in manufacturing, maintenance, and repair environments. Overall length is 2-15/16 inches, and thread length is 1-1/4 inches, fitting standard tap holders for the 3/8-inch size range.

Key Features

• 45-degree right-hand spiral flutes for upward chip evacuation in blind holes
• TiN coating reduces friction and extends tool life in ferrous materials
• Modified bottoming chamfer allows threading close to the bottom of blind holes
• Vanadium high-speed steel construction for toughness in interrupted cuts
• H3 thread limit holds 3B class of fit for standard mechanical assemblies
• 3-flute design balances chip clearance and thread-wall support

Compatibility

Designed for cutting 3/8-16 UNC internal threads in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. Compatible with standard tap holders and chucks accepting a 3/8-inch tap shank in the Series 303 OSG product line.

Installation Notes

Install in a rigid tap holder or floating tap chuck to minimize axial runout; excessive runout accelerates wear and can cause tap breakage. Ensure the workpiece is securely fixtured and the pilot hole diameter is correct for 3/8-16 UNC before tapping. Apply appropriate cutting fluid for the workpiece material, especially when threading stainless steel. Do not reverse the tap under power without confirming the machine control is set for proper back-off to avoid thread damage.