Osg 1206700 Spiral Point Tap 4-48 Unf 2 Flute Bottoming Hss

Product Description

The OSG 1206700 is a spiral point tap designed for threading 4-48 UNF holes in a wide range of metallic materials. Built from high-speed steel with a bright finish, this two-flute tap features a bottoming chamfer, making it suited for threading to the bottom of blind holes where full thread depth is required. At 1.875 inches overall length with a 0.319-inch thread length and 0.141-inch shank diameter, it is sized for small-fastener work in precision assemblies. The H2 thread limit and 2B class of fit deliver consistent tolerance control for standard unified fine-thread applications. Licensed machinists and toolroom technicians are the primary users.

This tap is used in machining and fabrication operations where 4-48 UNF internal threads are required. The bottoming chamfer configuration makes it appropriate for blind-hole applications in production and repair environments. The material application range covers aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel, giving it broad utility across general metalworking, aerospace component work, and maintenance machining. Right-hand thread direction is standard for conventional tapping operations on manual or CNC equipment.

Key Features

• Bottoming chamfer for threading to the bottom of blind holes
• High-speed steel construction for durability across a broad material range including hardened steel
• H2 thread limit with 2B class of fit for consistent tolerance in standard UNF applications
• Two-flute spiral point design to push chips forward during through-hole and shallow blind-hole tapping
• Bright finish with no coolant-through requirement, suitable for general shop use
• Right-hand thread direction compatible with standard tapping heads and CNC rigid tapping cycles

Compatibility

Designed for cutting 4-48 UNF internal threads per the OSG Series 105B product line. Suitable for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces.

Installation Notes

This tap should be installed and used by qualified machinists familiar with tapping operations and proper cutting fluid selection for the workpiece material. Ensure the workpiece is securely fixtured and the tap is aligned perpendicular to the drilled hole before engaging. For blind-hole applications using the bottoming chamfer, use a starting tap or plug tap first to establish the thread before switching to this bottoming tap. Follow applicable shop safety procedures and machine tool manufacturer guidelines when setting up tapping cycles.