Osg 2840808 Spiral Point Tap 5/16-18 Unc Ticn Hss

Product Description

The OSG 2840808 is a spiral point tap designed for threading through-holes in a wide range of ferrous and non-ferrous metals. Built from Vanadium High Speed Steel (HSS-E) and finished with a Titanium Carbonitride (TiCN) coating, this tap delivers extended tool life and reduced friction in demanding production environments. It cuts a 5/16-18 UNC right-hand internal thread to a 2B class of fit with a plug chamfer and H5 thread limit. Overall length measures 2.72 inches with a thread length of 0.665 inches and a shank diameter of 0.318 inches. Machinists, tool-and-die makers, and maintenance technicians use this tap in both CNC and manual tapping applications.

The 2840808 is suited for through-hole tapping in materials including aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, stainless steel, and cast iron. The 3-flute spiral point geometry pushes chips forward ahead of the cutting action, making it well-suited for through-hole work where chip evacuation is critical. The plug chamfer provides a gradual lead-in, making it appropriate for most general production tapping scenarios where a blind-hole bottom chamfer is not required.

Key Features

• 5/16-18 UNC thread form with 2B class of fit and H5 thread limit for consistent tolerance control
• TiCN coating reduces wear and built-up edge in ferrous and abrasive materials
• Vanadium HSS-E substrate provides toughness and heat resistance beyond standard M2 HSS
• 3-flute spiral point design pushes chips forward for reliable through-hole chip evacuation
• Plug chamfer for general-purpose lead-in in standard through-hole applications
• Right-hand cut, non-coolant-through, non-interrupted thread construction

Compatibility

Designed for through-hole tapping of 5/16-18 UNC threads across a broad range of workpiece materials including aluminum, stainless steel, alloy steel, die steel, cast iron, and low-, medium-, and high-carbon steel.

Installation Notes

Tapping operations should be performed by a qualified machinist following standard shop safety procedures. Secure the workpiece fully before beginning and ensure the tap is properly aligned with the pre-drilled hole to prevent tap breakage. Use an appropriate cutting fluid or tapping compound for the workpiece material to maximize tool life and thread quality. For CNC applications, verify spindle direction and feed rate settings before engaging the tap.