Osg 2885605 Spiral Point Tap 1/4-20 Unc Tin Hss

Product Description

The OSG 2885605 is a spiral point plug tap designed for threading 1/4-20 UNC holes in ferrous and non-ferrous workpieces. The spiral point geometry pushes chips forward ahead of the cutting zone, making it well suited for through-hole tapping applications where chip evacuation is critical. Ground from high-speed steel (HSS) stock and finished with a titanium nitride (TiN) coating, this tap delivers improved wear resistance and reduced friction compared to uncoated HSS. It carries a 2B class of fit and an H3 thread limit, producing threads that meet standard tolerance for most fastener assemblies.

This tap is rated for use in aluminum, cast aluminum, low-carbon steel, and medium-carbon steel. The plug chamfer distributes cutting load across the first few threads, making it the standard choice for general production tapping and repair work. It is commonly used in machine shops, maintenance facilities, and light manufacturing where 1/4-20 UNC threads are tapped frequently. The right-hand thread direction is compatible with conventional tapping spindles and hand tap handles. No coolant-through capability is present, so flood or brush-applied cutting fluid should be used for optimal tool life in steel.

Key Features

• Spiral point geometry advances chips forward — ideal for through-hole tapping
• TiN coating increases surface hardness and reduces built-up edge in aluminum and steel
• H3 thread limit and 2B class of fit for standard tolerance threaded assemblies
• Plug chamfer distributes cutting load for smooth thread formation in production use
• High-speed steel construction provides toughness for hand and machine tapping
• 2-flute design reduces torque requirements in softer materials

Compatibility

Rated for tapping aluminum, cast aluminum, low-carbon steel, and medium-carbon steel in 1/4-20 UNC through-hole applications.

Installation Notes

This tap should be installed and operated by a machinist or skilled maintenance technician familiar with tapping procedures. Secure the workpiece firmly before tapping and ensure the tap is aligned perpendicular to the drilled hole to avoid tap breakage. Apply cutting fluid appropriate for the workpiece material — sulfur-based fluid for steel, water-soluble or petroleum-based fluid for aluminum. Reverse the tap periodically when hand tapping to break chips and prevent galling.