Osg 1651505608 Spiral Point Tap 2-56 Unc Plug H2

Product Description

The OSG 1651505608 is a spiral point plug tap designed for right-hand threading in a 2-56 UNC configuration with a 2B class of fit. Built from powdered metal and finished with OSG EXOTAP VC-10 vanadium coating, it delivers extended wear resistance across a broad range of workpiece materials. The two-flute spiral point design pushes chips forward ahead of the cutting zone, making it well suited for through-hole tapping operations. Overall length is 1.772 inches with a thread length of 0.437 inches and an H2 thread limit for close tolerance control. The shank diameter measures 0.141 inches. This tap is installed by machinists, toolroom technicians, and maintenance trades working with small-diameter fastener threads.

This tap covers through-hole threading applications in alloy steel, aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, stainless steel, hardened steel, and die steel. The 2-56 UNC thread form is common in precision instrument work, electronics enclosures, and small mechanical assemblies where miniature fasteners are required. The plug chamfer provides a gradual lead-in, making it appropriate for production and repair environments alike.

Key Features

• EXOTAP VC-10 vanadium coating for improved tool life and heat resistance
• Powdered metal construction provides a consistent, fine-grain substrate for small-diameter tapping
• Spiral point geometry pushes chips forward, reducing clogging in through-hole applications
• H2 thread limit for consistent 2B class of fit tolerances
• Plug chamfer (3-5 thread lead) allows controlled thread engagement
• No coolant-through requirement simplifies setup on standard machine tools

Compatibility

Designed as an OEM-style replacement or direct-application tap for 2-56 UNC through-hole threading operations across the listed workpiece materials in Series 16515.

Installation Notes

This tap is installed by machinists or maintenance technicians using a tapping machine, CNC machining center, or hand tap wrench. The workpiece must be secured and the spindle aligned axially with the drilled hole before engagement. Power down or de-energize any CNC machine before tooling changes. Use an appropriate cutting fluid or tapping compound for the workpiece material to protect the coating and extend tool life.