Osg 1165102 Straight Flute Tap 1/4-20 Unc Plug Hss

Product Description

The OSG 1165102 is a straight flute tap designed for cutting internal threads in a range of ferrous and non-ferrous materials. Built from high-speed steel, it produces a 1/4-20 UNC right-hand thread with a plug chamfer that allows the thread to start gradually and run through to full depth. The tap features 3 flutes and carries an H2 thread limit, indicating a tolerance class suitable for general-purpose threading applications. Overall length is 2.5 inches with a thread length of 1 inch. Licensed machinists, tool and die technicians, pipefitters, and maintenance trades rely on this type of tap for production and repair threading tasks.

This tap is suited for through-hole and blind-hole tapping operations in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The plug chamfer style starts the tap with a gradual lead, making it appropriate for both hand tapping and machine tapping setups where a starting chamfer is needed before the full thread form is engaged. It is part of OSG Series 103 and is sold individually.

Key Features

• 1/4-20 UNC right-hand thread form for general fastener and fitting applications
• Plug chamfer provides gradual thread engagement for through-hole and blind-hole use
• High-speed steel construction offers durability across a wide range of workpiece materials
• H2 thread limit for standard general-purpose tolerance fits
• 3 straight flutes suitable for tapping shorter chip materials such as cast iron and aluminum
• Compact 2.5-inch overall length fits standard tap handles and CNC toolholders

Compatibility

Designed for use in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces. Fits standard 1/4-inch tap wrenches, T-handle tap holders, and machine tap chucks sized for this shank diameter.

Installation Notes

This tap is installed by machinists, maintenance technicians, and trade professionals using standard tap wrenches or machine tapping equipment. Always ensure the workpiece is securely fixtured before beginning the tapping operation. Use the appropriate cutting fluid or tapping oil for the workpiece material to extend tool life and improve thread quality. Inspect the tap for wear or chipping before each use and replace if the cutting edges show damage.