Osg 1230001 Spiral Point Tap 1/4-20 Unc 2 Flute Hss

Product Description

The OSG 1230001 is a spiral point tap designed for threading 1/4-20 UNC internal threads in a wide range of ferrous and non-ferrous materials. It features a plug chamfer, a 3B class of fit, and an H3 thread limit for controlled-tolerance output. Built from high-speed steel (HSS) with a steam oxide coating, this tap offers solid wear resistance and chip evacuation in moderate-production tapping applications. The spiral point geometry pushes chips forward ahead of the tap rather than backing them into the flute, making it well suited for through-hole threading. Overall length is 2.5 inches with a 0.638-inch threaded section.

This tap is intended for use in through-hole applications across a broad material range including low-carbon, medium-carbon, high-carbon, and hardened steel, as well as cast iron, aluminum, and cast aluminum. It is suited for machine tapping operations on CNC machining centers, turret lathes, and drill presses equipped with a tapping attachment or rigid tapping cycle. The 2-flute design and plug chamfer make it a standard choice for general-purpose production threading where hole depth exceeds thread depth.

Key Features

• Spiral point geometry pushes chips forward for clean through-hole threading
• H3 thread limit provides controlled oversize for 3B class of fit tolerancing
• High-speed steel construction handles steel, cast iron, and aluminum applications
• Steam oxide coating reduces friction and provides light corrosion resistance during storage and use
• Plug chamfer (7-10 thread lead) eases entry and is the standard choice for through-hole work
• Right-hand thread direction compatible with standard spindle rotation

Compatibility

Designed for through-hole tapping of 1/4-20 UNC threads per OSG Series 105. Rated for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. Not designed for coolant-through operation. Non-interrupted thread form only.

Installation Notes

This tap should be installed in a tap holder, collet chuck, or rigid tapping chuck appropriate for the shank diameter of 0.255 inches. Power down or bring the spindle to a full stop before changing tooling. Use an appropriate cutting fluid for the workpiece material to extend tap life and maintain thread quality. Follow ASME B94.9 standards for tap selection and machine tapping practices.