Osg 2855001 Spiral Point Tap 1/4-20 Unc 3 Flute Plug

Product Description

The OSG 2855001 is a spiral point tap designed for threading 1/4-20 UNC holes in a wide range of ferrous and non-ferrous materials. Manufactured from Vanadium High Speed Steel (HSS-E) with a steam oxide coating, this plug chamfer tap pushes chips forward ahead of the cutting edge, making it well suited for through-hole tapping operations. The H11 thread limit ensures controlled oversize tolerance for reliable fit with standard UNC fasteners. At 2.5 inches overall length with a 0.594-inch thread length, the 2855001 fits standard tap holders and is a direct-use replacement for production and maintenance work.

This tap is intended for through-hole applications in materials including aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, stainless steel, hardened steel, and cast iron. The three-flute geometry provides a balance of chip clearance and cutting stability across this broad material range. Typical use cases include production tapping on CNC machining centers, drill presses, and manual tapping operations in job shops, maintenance facilities, and manufacturing environments.

Key Features

• Spiral point design pushes chips forward for clean through-hole tapping
• Vanadium High Speed Steel (HSS-E) construction for extended tool life in tough materials
• Steam oxide coating reduces friction and improves lubricity during cutting
• H11 thread limit provides controlled oversize tolerance for standard UNC fit
• Right-hand thread direction, 3 flutes, plug chamfer entry
• No coolant-through required — suitable for conventional flood or manual lubrication

Compatibility

Designed for through-hole tapping of 1/4-20 UNC threads across aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, stainless steel, hardened steel, and cast iron. Compatible with standard 1/4-inch tap holders and chucks accepting a 0.255-inch shank diameter.

Installation Notes

Install in a standard tap holder or chuck rated for the shank diameter before use. Always apply cutting fluid or tapping compound appropriate for the workpiece material to extend tap life and improve thread quality. Ensure the workpiece is securely fixtured and that the tap is aligned perpendicular to the drilled hole before engagement. Follow applicable shop safety practices and use appropriate RPM settings for the material being tapped.