Osg 1009108 Straight Flute Tap 1/4-20 Unc Ticn Hss

Product Description

The OSG 1009108 is a straight flute tap designed for cutting 1/4-20 UNC internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel with a TiCN coating, this tap delivers improved wear resistance and extended tool life compared to uncoated HSS tools. It features a modified bottoming chamfer, making it suitable for threading holes that require thread engagement close to the bottom. With 4 flutes, a 2.5-inch overall length, and a thread length of approximately 1 inch, it is sized for standard hand-tap and machine-tap applications in production and maintenance settings. The H11 thread limit designation indicates an oversize tolerance class suitable for use with coatings or in applications requiring a slightly larger thread fit.

This tap is intended for tapping operations in materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The modified bottoming chamfer allows threading in blind holes where a standard taper or plug tap cannot reach full depth. It is suited for use in machine shops, maintenance and repair operations, and production environments where consistent 1/4-20 UNC threads are required. A right-hand thread direction is standard for conventional threaded fastener applications.

Key Features

• TiCN coating increases surface hardness and lubricity, extending tool life in steel and cast iron
• Modified bottoming chamfer allows threading close to the bottom of blind holes
• H11 thread limit with oversize designation accommodates coating buildup and provides proper fit
• 4-flute straight flute design provides chip control in through-hole and shallow blind-hole applications
• High-speed steel construction handles a broad range of workpiece materials without chipping
• Coolant-through feature not required, compatible with external flood or mist coolant delivery

Compatibility

Designed for tapping 1/4-20 UNC threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. Part of the OSG Series 101H straight flute tap line.

Installation Notes

This tap should be installed by a machinist or maintenance technician familiar with hand or machine tapping operations. Always ensure the workpiece is securely fixtured and the tap is properly aligned before starting the cut to avoid tap breakage. Power down or de-energize any machine tool before mounting or removing the tap from the holder. Follow applicable shop safety practices and use a compatible cutting fluid or tapping compound appropriate for the workpiece material to reduce tool wear and improve thread quality.