Osg 1110400 Straight Flute Tap 1/4-28 Unf Plug Hss

Product Description

The OSG 1110400 is a straight flute plug tap designed for cutting right-hand internal threads in a range of ferrous and non-ferrous materials. Built from high-speed steel with a bright uncoated finish, it produces 1/4-28 UNF threads and is suited for through-hole and blind-hole tapping applications where chip evacuation follows the flute direction. The plug chamfer - typically 3 to 5 threads - provides a moderate lead-in that balances starting ease with thread engagement depth. With a 2.5 inch overall length and a 1 inch thread length, this tap fits standard tap wrenches and machine tap holders used in manual and CNC operations.

This tap is intended for production and maintenance tapping in machine shops, fabrication facilities, and field repair scenarios. It is well suited for threading aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The straight flute geometry makes it appropriate for through-hole applications and short blind holes where chips can be pushed ahead or cleared easily. Machinists, tool and die makers, and maintenance technicians are the primary users.

Key Features

• 1/4-28 UNF thread form for fine-pitch unified national thread applications
• 4 straight flutes for rigidity and consistent chip handling in through-hole work
• Plug chamfer (approximately 3 to 5 thread lead-in) for balanced starting and full thread engagement
• High-speed steel construction provides toughness across a broad range of workpiece materials
• Bright uncoated finish suitable for use with standard cutting fluids and tapping compounds
• H2 thread limit for close tolerance fits in standard UNF threaded assemblies

Compatibility

Designed as an OEM-style straight flute plug tap for 1/4-28 UNF threading operations in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces.

Installation Notes

Always secure the workpiece and use a properly aligned tap wrench or machine holder to prevent tap breakage. Apply a suitable cutting fluid or tapping compound for the workpiece material before and during tapping. Back off periodically to break chips when tapping deeper holes. Follow applicable shop safety practices and ensure the tap is fully stopped before handling or changing tooling.