Hertel K008409AS Straight Flute Tap 5/16-24 Unf Hss

Product Description

The HERTEL K008409AS is a straight flute hand tap designed to cut internal threads in through-holes and shallow blind holes. It carries a 5/16-24 UNF thread form with a plug chamfer, which provides a moderate lead-in of approximately 3 to 5 threads before full thread engagement begins. Made from high-speed steel with a bright, uncoated finish, this tap delivers reliable performance in ferrous and non-ferrous materials. The H3 thread limit holds tolerances appropriate for a 3B class of fit, making it suitable for standard fastener assembly applications in production and maintenance work.

This tap is used in machine shops, maintenance facilities, and fabrication environments where unified fine threads are required. The 4-flute straight flute design is well-suited for through-hole tapping and for use in materials that produce short, breakable chips. It is appropriate for use in hand tapping operations or with a tapping machine at controlled feed rates. Typical applications include threading steel, aluminum, brass, and similar workpiece materials in general mechanical assembly and repair.

Key Features

• 5/16-24 UNF thread form for unified fine-thread applications
• Plug chamfer with approximately 3 to 5 thread lead-in for controlled entry
• H3 thread limit maintains 3B class of fit tolerances
• 4 straight flutes suited for through-hole tapping and short-chip materials
• High-speed steel construction for durability across common workpiece materials
• Bright, uncoated finish with no coolant-through requirement

Compatibility

Designed as a standard replacement or production tap for applications requiring a 5/16-24 UNF, 3B class of fit internal thread in through-hole or shallow blind-hole configurations.

Installation Notes

This tap should be installed and used by qualified machinists or maintenance technicians familiar with threading operations. Always secure the workpiece and align the tap perpendicular to the drilled hole before beginning. Power down any machine before changing or installing taps, and use appropriate cutting fluid for the workpiece material to extend tool life and improve thread quality. Do not force the tap if resistance increases suddenly, as this may indicate chip buildup or misalignment.