Osg 2840008 Spiral Point Tap 1/4-20 Unc Ticn Hss

Product Description

The OSG 2840008 is a spiral point tap designed for cutting 1/4-20 UNC internal threads in a wide range of ferrous and non-ferrous materials. Built from vanadium high speed steel (HSS-E) and finished with a titanium carbonitride (TiCN) coating, this tap delivers extended tool life in demanding production and maintenance environments. It features a plug chamfer, 3 flutes, a 2B class of fit, and right-hand thread direction. The H5 thread limit ensures consistent dimensional accuracy within tight tolerance bands. Overall length is 2.5 inches with a thread length of 0.594 inches and a shank diameter of 0.255 inches. Machinists, tool-and-die technicians, and maintenance mechanics are the primary users.

This tap is suited for tapping 1/4-20 UNC through-holes in materials including aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, and stainless steel. The spiral point geometry pushes chips forward ahead of the tap, making it most effective in through-hole applications where chip evacuation is not obstructed. It is appropriate for both CNC tapping cycles and hand-tapping operations in general machining, fabrication, and repair work.

Key Features

• 1/4-20 UNC thread form, right-hand, 2B class of fit
• Vanadium high speed steel (HSS-E) construction for wear resistance in tough materials
• TiCN coating reduces friction and increases surface hardness for longer tool life
• 3-flute spiral point design pushes chips forward, optimized for through-hole tapping
• H5 thread limit for consistent tolerance control in precision applications
• Plug chamfer provides gradual thread engagement and reduced starting torque

Compatibility

Designed as an OEM-style replacement or direct-use tap for 1/4-20 UNC through-hole tapping operations across aluminum, stainless steel, alloy steel, die steel, cast iron, and carbon steel workpieces. Compatible with standard 1/4-inch tap holders, tapping heads, and CNC rigid-tap collet chucks sized for a 0.255-inch shank.

Installation Notes

Always secure the workpiece and use the correct tap holder or chuck before beginning a tapping operation. Apply appropriate cutting fluid for the workpiece material — sulfurized oil for steels, water-soluble coolant or kerosene for aluminum — to reduce heat and extend tap life. For CNC applications, verify that the machine is programmed for rigid tapping mode and that spindle speed and feed rate match the tap manufacturer recommendations for the material being cut. Inspect the tap for wear or chipping before each use; a damaged tap can seize in the hole and result in breakage.