Osg 1121908 Straight Flute Tap 7/16-14 Unc Plug Hss Ticn

Product Description

The OSG 1121908 is a straight flute plug tap designed for cutting internal threads in a wide range of ferrous and non-ferrous materials. It threads 7/16-14 UNC right-hand threads and is manufactured from high-speed steel with a TiCN (titanium carbonitride) coating that extends tool life and reduces friction at the cutting edge. The plug chamfer - typically 3 to 5 threads - makes it suitable for through-hole and moderately deep blind-hole applications. With a 4-flute geometry and H3 thread limit, this tap holds tight tolerances and provides stable chip control in production and maintenance threading operations. It is installed by machinists, millwrights, and tool-and-die professionals.

This tap is suited for use in manual and CNC tapping operations on aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The H3 thread limit accommodates standard tolerance class 2B threaded holes, which covers the majority of general mechanical assembly work. It is a practical choice for job shops, maintenance departments, and production facilities requiring consistent 7/16-14 UNC thread quality across a range of base materials.

Key Features

• 7/16-14 UNC right-hand thread form with H3 thread limit for standard 2B tolerance holes
• Plug chamfer provides versatile use in through-holes and moderate-depth blind holes
• TiCN coating improves wear resistance and reduces built-up edge on aluminum and steel
• 4-flute straight design delivers stable cutting action and chip control
• High-speed steel construction balances toughness and cutting performance
• No coolant-through requirement - compatible with flood coolant or cutting oil applied externally

Compatibility

Rated for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Designed for standard 7/16-14 UNC tapping operations in both manual tap handles and CNC rigid-tapping setups that accept straight-shank taps.

Installation Notes

Use appropriate cutting fluid or tapping compound for the workpiece material before starting - this is especially important on steel to prevent galling. Ensure the tap is aligned perpendicular to the workpiece surface to avoid thread runout or tap breakage. In manual operation, reverse the tap a half-turn periodically to break chips. Always secure the workpiece firmly and observe standard shop-safety practices when operating drill presses or milling machines.