Osg 1122505 Straight Flute Tap 1/2-13 Unc Tin Hss

Product Description

The OSG 1122505 is a straight flute tap designed to cut 1/2-13 UNC internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel (HSS) with a titanium nitride (TiN) coating, this plug chamfer tap delivers extended tool life and reduced friction during threading operations. It features 4 flutes, a right-hand thread direction, and is manufactured to a 3B class of fit with an H3 thread limit, making it suitable for standard tolerance threaded fastener applications in production and maintenance environments. Licensed machinists and toolroom technicians are the primary users of this tool.

This tap is suited for threading operations in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The plug chamfer style — with its moderate lead-in — is the standard choice for through-hole threading and the most common general-purpose starting point in machine shop and field maintenance work. The TiN coating helps extend tool life when running at higher speeds or in abrasive materials. The OSG Series 101 designation places this tap within a well-established product family for standard UNC threading applications.

Key Features

• 1/2-13 UNC right-hand thread, 3B class of fit, H3 thread limit for standard tolerance control
• Plug chamfer provides a moderate lead-in — appropriate for through-hole and most blind-hole applications
• High-speed steel construction provides toughness across a broad range of workpiece materials
• TiN coating reduces friction and heat buildup, extending tool life compared to uncoated HSS
• 4 straight flutes for chip clearance in short-chipping materials such as cast iron and aluminum
• No coolant-through design — compatible with flood, mist, or manual lubrication methods

Compatibility

Designed for threading aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces requiring a 1/2-13 UNC, 3B class of fit internal thread.

Installation Notes

This tap is installed by machinists or toolroom technicians using a tapping head, CNC machine, or tap wrench. Always secure the workpiece and ensure the tap is aligned perpendicular to the hole before engagement. Use an appropriate cutting fluid or tapping compound for the workpiece material to prevent galling and extend tool life. Do not force a worn or chipped tap — inspect the cutting edges before each use.