Osg 1215601 Spiral Point Tap 2-56 Unc Plug Hss

Product Description

The OSG 1215601 is a spiral point tap designed for right-hand threading in a wide range of ferrous and non-ferrous materials. It cuts a 2-56 UNC thread profile using a 2-flute, plug chamfer geometry that drives chips forward ahead of the cut, reducing clogging in through-hole applications. The tap is manufactured from high-speed steel and finished with a steam oxide coating that improves lubricity and corrosion resistance during use. Overall length is 1.75 inches with a thread length of 0.441 inches and a shank diameter of 0.141 inches. Thread limit is H5, indicating a tighter tolerance class suited for controlled-fit thread requirements.

This tap is used in machine shop, maintenance, and precision assembly applications where small-diameter 2-56 UNC threads are required. It is suited for through-hole tapping in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. The plug chamfer makes it a standard choice for production tapping where a starting chamfer is acceptable and chip evacuation through the hole is feasible. It does not feature coolant-through capability and is not designed for interrupted thread applications.

Key Features

• 2-56 UNC right-hand thread profile for small-diameter fastener applications
• Plug chamfer geometry drives chips forward, ideal for through-hole tapping
• High-speed steel construction provides durability across a broad material range
• Steam oxide finish improves lubricity and reduces galling during cutting
• H5 thread limit for controlled, tighter-tolerance thread fit
• Compact overall length of 1.75 inches suitable for close-quarter machine setups

Compatibility

Designed as a standard replacement or production tap for 2-56 UNC through-hole tapping operations across aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces.

Installation Notes

This tap is installed and operated by machinists or maintenance technicians using a tapping machine, CNC machining center, or hand tap wrench with appropriate alignment. Always secure the workpiece firmly and ensure the tap is properly aligned with the pilot hole before beginning the cut. Coolant or tapping fluid appropriate for the workpiece material should be applied to extend tool life and improve thread quality. Inspect the tap for wear or chipping before each use, as small-diameter taps are susceptible to breakage under side load or misalignment.