Osg 1230201 Spiral Point Tap 1/4-20 Unc Hss Oxide

Product Description

The OSG 1230201 is a spiral point tap designed for threading 1/4-20 UNC internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel with a steam oxide coating, it offers solid wear resistance and lubricity for general production threading work. The plug chamfer allows gradual thread engagement, making it suitable for through-hole applications. With 3 flutes and an H3 thread limit, this tap maintains consistent thread tolerance to a 3B class of fit. It measures 2.5 inches overall in length with a 0.638-inch thread length and a 0.255-inch shank diameter. Licensed HVAC, plumbing, and mechanical contractors as well as machine shop professionals will find it suited to repetitive threading tasks on the bench or in a drill press setup.

This tap is intended for through-hole threading operations where chips are pushed forward and cleared ahead of the cutting edges. It performs across a broad material range including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. The right-hand thread direction and standard UNC form make it a common choice for replacement fastener thread repairs and new fabrication work in light industrial and maintenance environments.

Key Features

• 1/4-20 UNC thread form with H3 thread limit and 3B class of fit for controlled tolerance threading
• 3-flute spiral point geometry pushes chips forward, ideal for through-hole applications
• High-speed steel construction provides durability across a wide range of workpiece materials
• Steam oxide coating reduces friction and improves chip evacuation during cutting
• Plug chamfer allows gradual thread engagement for smooth, stable entry
• Right-hand thread direction, no coolant-through, non-interrupted thread form

Compatibility

Compatible with aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces requiring 1/4-20 UNC right-hand internal threads in through-hole configurations.

Installation Notes

This tap is installed by a machinist or maintenance technician using a standard tap wrench, tapping head, or drill press with appropriate tapping attachment. Always ensure the workpiece is secured and the pilot hole diameter is correctly sized for a 1/4-20 UNC thread before beginning. Apply cutting fluid appropriate to the workpiece material and back off periodically to break chips when tapping by hand. Follow applicable shop safety and tooling manufacturer guidelines for speeds and feeds when using power equipment.