Osg 1120008 Straight Flute Tap 1/4-20 Unc Ticn Hss

Product Description

The OSG 1120008 is a straight flute tap designed for cutting 1/4-20 UNC internal threads in a wide range of ferrous and non-ferrous workpiece materials. It is manufactured from high-speed steel with a TiCN (titanium carbonitride) coating that improves surface hardness and wear resistance for extended tool life. The tap features a taper chamfer, which distributes cutting load gradually across the leading threads and makes it well-suited for through-hole applications. With 4 flutes and an H3 thread limit, it holds close tolerances and meets 3B class of fit requirements. Machinists and toolroom technicians install this tap in drill presses, CNC machining centers, and hand tapping operations.

This tap is intended for production and maintenance tapping in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Its straight flute geometry works best in through holes where chips can exit freely ahead of the tool. The taper chamfer entry makes it a reliable choice for starting threads squarely, particularly in manual and semi-automated setups where the operator controls feed alignment.

Key Features

• 1/4-20 UNC thread form with right-hand thread direction
• TiCN coating increases surface hardness and reduces friction for longer tool life
• Taper chamfer distributes cutting forces across multiple leading threads for smooth entry
• H3 thread limit maintains 3B class of fit tolerances
• 4 straight flutes support chip clearance in through-hole applications
• High-speed steel construction provides toughness across a broad range of workpiece materials

Compatibility

Designed as an OEM-style straight flute tap for through-hole 1/4-20 UNC threading operations in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces.

Installation Notes

This tap is installed and used by machinists and toolroom technicians in drill presses, tapping machines, or by hand with a tap wrench. Always ensure the pilot hole is drilled to the correct tap drill diameter for 1/4-20 UNC before beginning the tapping operation. Use appropriate cutting fluid for the workpiece material to reduce heat and extend tool life. Secure the workpiece firmly before tapping to prevent movement and thread misalignment.