Osg 1242400 Spiral Point Tap 1/2-13 Unc 3 Flute Plug Hss

Product Description

The OSG 1242400 is a spiral point tap designed for threading 1/2-13 UNC through-holes in a wide range of ferrous and non-ferrous materials. Manufactured from high-speed steel with a bright finish, it features a plug chamfer and a right-hand thread direction, making it suited for conventional tapping operations on CNC machines and manual tap handles alike. The H5 thread limit provides consistent sizing within the 2B class of fit tolerance. With three flutes and a spiral point geometry, the tap pushes chips forward ahead of the cut rather than backing them into the flute, which reduces chip packing in through-hole applications.

This tap is intended for production and job-shop environments where through-hole 1/2-13 UNC threads are required. Rated material applications include aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel, making it a versatile choice for general machining work in automotive, fabrication, and maintenance repair operations. The plug chamfer style is the standard starting point for most through-hole tapping where a bottoming or taper style is not specified.

Key Features

• Spiral point geometry pushes chips forward, reducing chip packing in through-hole applications
• 1/2-13 UNC thread form with H5 thread limit and 2B class of fit for standard tolerance threading
• High-speed steel construction handles a broad range of workpiece materials including hardened steel
• Plug chamfer provides reliable thread lead-in for through-hole tapping
• Bright finish with no coolant-through requirement, compatible with flood or manual lubrication
• Right-hand thread direction for standard tapping setups

Compatibility

Designed as a standard replacement or production spiral point tap for 1/2-13 UNC through-hole threading in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces.

Installation Notes

Install in a tap holder, tapping head, or rigid CNC tapping cycle appropriate for the machine setup. Ensure the spindle is fully stopped and the workpiece is securely fixtured before tool changes. Apply cutting fluid or tapping compound appropriate for the workpiece material to extend tool life and improve thread finish. Follow OSHA machine guarding and lockout/tagout procedures when setting up tapping operations on powered equipment.