Osg 1230101 Spiral Point Tap 1/4-20 Unc 2 Flute 3B Hss

Product Description

The OSG 1230101 is a spiral point tap designed for threading 1/4-20 UNC holes in a wide range of ferrous and non-ferrous metals. It features a 2-flute bottoming chamfer geometry, which allows threading close to the bottom of a blind hole. Made from high-speed steel with a steam oxide coating, it delivers consistent thread quality under production conditions. The 3B class of fit and H3 thread limit ensure threads meet standard tolerance requirements for most mechanical assemblies. Overall length is 2.5 inches with a thread length of 0.638 inches and a shank diameter of 0.255 inches.

This tap is suited for hand tapping and machine tapping operations in general manufacturing, maintenance, and repair environments. The bottoming chamfer makes it the right choice when a full-form thread is required to the base of a blind hole. Compatible material applications include aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. Right-hand thread direction is standard for most UNC fastener applications. This is a single-piece item sold individually.

Key Features

• 1/4-20 UNC thread form with 3B class of fit and H3 thread limit for precise tolerance control
• Bottoming chamfer geometry for threading to the base of blind holes
• High-speed steel construction provides durability across a broad range of workpiece materials
• Steam oxide coating reduces friction and offers basic corrosion resistance during use
• Right-hand thread direction, no coolant-through requirement, non-interrupted thread design
• Compact 2.5-inch overall length suits bench, drill press, and CNC tapping operations

Compatibility

Designed for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces requiring 1/4-20 UNC right-hand threads to 3B tolerance.

Installation Notes

Install and operation should be performed by a machinist or qualified technician familiar with tapping procedures and cutting fluid requirements for the workpiece material. Ensure the workpiece is securely clamped and the tap is properly aligned before engagement to avoid tap breakage. Use appropriate cutting fluid for the material being tapped. Follow applicable shop safety standards when operating tapping equipment.