Osg 1650502408 Spiral Flute Tap 3/8-16 Unc Ticn Coated

Product Description

The OSG 1650502408 is a spiral flute tap designed for cutting 3/8-16 UNC right-hand internal threads in a wide range of ferrous and non-ferrous metals. Built from powdered metal (grade PMT15) and coated with TiCN (Titanium Carbonitride), this tap delivers improved wear resistance and heat dissipation compared to standard high-speed steel tooling. It features a modified bottoming chamfer for threading close to the bottom of blind holes and a 45-degree helix angle that evacuates chips efficiently in the direction of the cut. Overall length is 3.54 inches (100 mm) with a thread length of 0.5 inches (12.7 mm). Licensed machinists and tool-and-die professionals specify this tap when tight tolerances and longer tool life matter in production environments.

This tap is suited for blind-hole threading applications across a broad material range including low-, medium-, and high-carbon steel, alloy steel, cast iron, cast aluminum, aluminum, and stainless steel. The 2B class of fit and H5 thread limit make it appropriate for standard commercial and precision fastener assemblies. The spiral flute geometry is particularly effective in shorter-chipping materials where straight-flute taps tend to pack chips. It is appropriate for use in CNC machining centers, tapping heads, and manual tapping operations with controlled feed.

Key Features

• 3/8-16 UNC right-hand thread, 2B class of fit, H5 thread limit for consistent tolerance control
• 45-degree right-hand spiral flute design evacuates chips up and out of blind holes
• Modified bottoming chamfer allows threading to within a few threads of hole bottom
• TiCN coating increases surface hardness and reduces friction against hard and abrasive workpiece materials
• Powdered metal construction (PMT15 grade) provides finer grain structure and higher toughness than conventional HSS
• No coolant-through requirement — suitable for flood coolant or cutting oil external application

Compatibility

Designed for threading 3/8-16 UNC blind holes in alloy steel, aluminum, cast aluminum, cast iron, hardened steel, high-carbon steel, low-carbon steel, medium-carbon steel, and stainless steel workpieces. Part of OSG Series 16505.

Installation Notes

This tap should be installed by a qualified machinist following standard tapping procedures for the workpiece material and hole depth. Secure the workpiece and ensure the tapped hole is pre-drilled to the correct tap drill diameter for 3/8-16 UNC before starting. Apply appropriate cutting fluid or tapping compound for the material being threaded; do not run the tap dry in steel or stainless. When using in a CNC application, program feed rate to match the 16 TPI pitch exactly to avoid tap breakage or thread form errors.