Osg 1651506108 Spiral Point Tap 1/4-32 Unef Plug 3B

Product Description

The OSG 1651506108 is a spiral point tap in the EXOTAP VC-10 series, designed for cutting internal 1/4-32 UNEF threads in through-hole applications. The spiral point geometry pushes chips ahead of the cutting edge, keeping the flutes clear and reducing the risk of chip packing in production environments. It carries an H3 thread limit and a 3B class of fit, meaning it produces threads within tighter tolerance ranges suited to precision fastener applications. The powdered metal construction paired with OSG V coating provides improved wear resistance and heat dissipation compared to standard high-speed steel taps. Overall length is 3.15 inches with a thread length of 0.586 inches.

This tap is suited for threading operations in alloy steel, aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, medium-carbon steel, stainless steel, hardened steel, and die steel. The plug chamfer style makes it appropriate for through-hole tapping where the tap can advance freely through the workpiece. It is a right-hand tap with a 0.255-inch shank diameter, compatible with standard tap holders and CNC tooling setups. Coolant-through capability is not available on this tap. It is packaged individually and well suited to both manual and machine tapping operations in job shop and production machining environments.

Key Features

• Spiral point geometry pushes chips forward, reducing chip packing in through-hole tapping
• Powdered metal construction provides higher wear resistance than standard HSS
• V coating reduces friction and extends tool life across a broad range of work materials
• H3 thread limit with 3B class of fit for precision thread tolerance control
• Plug chamfer for clean entry in through-hole applications
• Right-hand thread direction, compatible with standard tap holders and CNC spindles

Compatibility

Designed for through-hole tapping in alloy steel, aluminum, cast aluminum, cast iron, hardened steel, high-carbon steel, low-carbon steel, medium-carbon steel, stainless steel, and die steel. Part of OSG Series 16515 EXOTAP VC-10.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians. Before mounting, verify that the tap holder and spindle are clean and free of debris to ensure accurate alignment. Interrupted thread and oversize features are not present on this tap, so proper drilling to the correct tap drill diameter for 1/4-32 UNEF is essential before tapping. Always follow machine shop safety practices including appropriate speeds and feeds for the specific work material being tapped.