Osg 1660500000 Spiral Flute Tap 1/4-20 Unc Solid Carbide

Product Description

The OSG 1660500000 is a solid carbide spiral flute tap designed for cutting 1/4-20 UNC right-hand internal threads in demanding production and maintenance applications. With a 15-degree helix angle and three right-hand spiral flutes, this tap efficiently evacuates chips upward out of the hole, making it well suited for blind-hole tapping. The modified bottoming chamfer allows threading close to the bottom of a bore. An H5 thread limit holds a normal class of fit, and the bright uncoated finish is standard for solid carbide tooling running in non-ferrous materials. Coolant-through capability supports higher feed rates and extended tool life in appropriate setups.

This tap is intended for use on aluminum, cast aluminum, and cast iron workpieces. It is a good fit for CNC machining centers, tapping heads, and rigid tapping setups in job shops, production floors, and MRO environments. Machinists and tool-and-die professionals working with 1/4-20 UNC fastener holes in light alloy or iron castings will find this tap appropriate for both through-hole and blind-hole applications requiring threading near the bottom of the bore.

Key Features

• Solid carbide construction for rigidity and wear resistance in abrasive or high-volume applications
• Spiral flute geometry with 15-degree helix angle for upward chip evacuation in blind holes
• Modified bottoming chamfer allows threading closer to hole bottom than standard plug chamfer taps
• Coolant-through design supports flood or through-spindle coolant delivery
• H5 thread limit with normal class of fit for standard 1/4-20 UNC thread tolerances
• Bright uncoated finish optimized for aluminum and cast aluminum applications

Compatibility

Rated for use in aluminum, cast aluminum, and cast iron. Designed for 1/4-20 UNC tapping in rigid setups on CNC machines or manual tapping equipment capable of maintaining true axial alignment.

Installation Notes

This tap is intended for installation and use by qualified machinists familiar with carbide tooling requirements. Solid carbide taps are brittle compared to high-speed steel alternatives and require rigid, properly aligned tapping setups to avoid breakage. Always verify spindle runout and alignment before use, and confirm the through-coolant supply is active if the tap is being run at elevated feeds. Follow applicable workplace safety procedures when handling cutting tools.