Osg 1749501 Spiral Flute Tap 10-24 Unc Bottoming 2B Hss

Product Description

The OSG 1749501 is a spiral flute tap designed to cut 10-24 UNC internal threads in a bottoming configuration. It is manufactured from vanadium high-speed steel and finished with a steam oxide coating, which reduces friction and helps resist corrosion during cutting operations. The 45-degree helix angle and three right-hand spiral flutes are engineered to evacuate chips efficiently in blind-hole applications, making it well suited for production threading and maintenance work. At 2-3/8 inches overall length with a 0.327-inch thread length, it fits standard tapping chucks and hand-tap wrenches used in machine shop and field environments.

This tap is intended for threading blind holes where a bottoming chamfer is required to maximize thread engagement close to the hole bottom. It carries a 2B class of fit, which is the standard tolerance for most general-purpose UNC threaded fastener applications. The H5 thread limit supports consistent fit across production runs. Suitable material applications include stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel, making it a versatile choice for machine shops, maintenance technicians, and fabrication professionals working with ferrous materials.

Key Features

• Bottoming chamfer allows threading to within a few threads of the bottom of a blind hole
• 45-degree helix angle promotes upward chip evacuation in blind-hole tapping
• Vanadium high-speed steel construction provides wear resistance in ferrous materials
• Steam oxide coating reduces friction and provides light corrosion resistance
• H5 thread limit ensures 2B class of fit for standard UNC fastener compatibility
• Right-hand flute direction and right-hand thread for use with standard tapping equipment

Compatibility

Designed for cutting 10-24 UNC right-hand internal threads in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces. OSG Series 303 spiral flute design. Coolant-through capability is not available on this tap.

Installation Notes

This tap is installed by machinists and maintenance technicians using a tapping chuck, CNC machine spindle, or hand-tap wrench. Always ensure the tap is properly aligned with the drilled hole before engagement to prevent tap breakage. Use an appropriate cutting fluid for the workpiece material, particularly when threading stainless steel. Inspect the hole diameter against the recommended tap drill size for 10-24 UNC before tapping to maintain the specified class of fit.