Osg 1211000 Spiral Point Tap 3-48 Unc 2 Flute Hss

Product Description

The OSG 1211000 is a spiral point tap designed for threading 3-48 UNC holes in a wide range of metals. The spiral point geometry pushes chips forward ahead of the cutting zone, making it well suited for through-hole tapping where chip evacuation is critical. Ground from high-speed steel (HSS) with a bright finish, it carries an H3 thread limit for consistent tolerance control. At 1.813 inches overall length with a 0.141-inch shank diameter, this is a compact tap sized for small-fastener work. It is installed and operated by machinists, tool and die makers, and maintenance technicians.

This tap is intended for through-hole tapping applications across a broad spectrum of workpiece materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. The plug chamfer style provides a gradual lead-in, distributing cutting load across several threads at the start of the cut. With 2 flutes and right-hand thread direction, it is compatible with standard CNC tapping cycles and hand-tapping equipment. Series 105 identifies the OSG product family for this geometry and size.

Key Features

• Spiral point geometry pushes chips forward for clean through-hole tapping
• H3 thread limit provides consistent tolerance for 3-48 UNC threads
• High-speed steel construction supports tapping in ferrous and non-ferrous materials
• Plug chamfer distributes cutting load gradually at thread entry
• Bright finish with no coolant-through requirement simplifies setup
• Right-hand cut, 2-flute design compatible with standard tapping equipment

Compatibility

Designed for through-hole tapping of 3-48 UNC threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces.

Installation Notes

This tap is installed by machinists or maintenance technicians using a tap wrench, tapping head, or CNC machine with a synchronized tapping cycle. Ensure the workpiece is securely clamped and the pilot hole diameter is correct for 3-48 UNC before starting. Use appropriate cutting fluid for the workpiece material to extend tool life and improve thread finish. Inspect the tap for wear or chipping before each use, as a damaged tap can strip threads or break in the hole.