Osg 1122808 Straight Flute Tap 1/2-20 Unf Ticn Hss

Product Description

The OSG 1122808 is a straight flute tap designed for cutting 1/2-20 UNF internal threads in a range of ferrous and non-ferrous materials. Built from high-speed steel (HSS) with a titanium carbonitride (TiCN) coating, it delivers increased surface hardness and wear resistance compared to uncoated taps. The plug chamfer (3-5 threads) allows the tap to be started in a through-hole or a blind hole with adequate clearance. It carries a 3B class of fit and an H3 thread limit, producing threads within tight dimensional tolerances. Machinists, tool-and-die makers, and maintenance technicians reach for this tap in both production and repair applications.

The 1122808 is suited for through-hole and blind-hole threading in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. At 3-3/8 inches overall length with a 1-21/32 inch thread length, it fits standard tap handles, tapping heads, and CNC rigid-tapping setups. Right-hand thread direction is standard. The 4-flute straight configuration works best in materials that produce short, broken chips rather than long stringy ones, making it a practical choice for the listed ferrous and aluminum alloys.

Key Features

• 1/2-20 UNF thread form, right-hand direction, 3B class of fit
• H3 thread limit for consistent, close-tolerance thread production
• TiCN coating increases hardness and reduces friction for longer tool life
• 4 straight flutes suited to short-chipping aluminum and ferrous materials
• Plug chamfer starts easily in through-holes and blind holes with clearance
• No coolant-through requirement - compatible with flood, mist, or paste lubricants

Compatibility

Designed for use in materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Fits standard 1/2-inch tap handles and tapping heads sized for the 0.367-inch shank diameter.

Installation Notes

Tapping operations should be performed by a qualified machinist or maintenance technician following shop safety procedures. Secure the workpiece fully before starting; never tap freehand in a drill press without a proper tap guide or self-reversing tapping head. Apply an appropriate cutting fluid or tapping paste for the workpiece material before and during tapping to protect the tool edge and achieve a clean thread form. Inspect the tap for chipping or wear before each use, and back the tap out periodically to clear chips when working in blind holes.