Hertel K017032AS Spiral Point Tap 4-40 Unc Left Hand Hss

Product Description

The HERTEL K017032AS is a left-hand spiral point tap designed for cutting internal threads in through-hole applications. It is manufactured from high-speed steel with a bright, uncoated finish and carries a 4-40 UNC thread form with a plug chamfer and H2 thread limit. The 2-flute spiral point geometry pushes chips forward ahead of the cutting zone, making it well suited for production tapping in through holes where chip evacuation is a priority. This tap is specified for a 2B and 3B class of fit, covering both standard and close-tolerance threading requirements. Machinists and toolroom technicians are the primary users of this tap.

This tap is intended for use in machine tapping operations on through-hole workpieces. The left-hand thread direction makes it appropriate for applications that require reverse-threaded fasteners or for use on left-hand threaded components. The 4-40 UNC designation is common in precision instrument assembly, electronics enclosures, and light mechanical hardware. It is designed for use in CNC machining centers, drill presses, and tapping arms operating with appropriate cutting fluid or lubrication for high-speed steel tooling.

Key Features

• Left-hand thread direction for reverse-threaded or left-hand thread applications
• Spiral point geometry pushes chips forward, optimizing performance in through-hole tapping
• 4-40 UNC thread form with plug chamfer for standard through-hole entry and lead-in
• H2 thread limit provides consistent fit within 2B and 3B class-of-fit tolerance range
• High-speed steel construction offers durability across a wide range of workpiece materials
• Bright uncoated finish — no coolant-through feature, suitable for use with external cutting fluid

Compatibility

Designed for through-hole tapping operations requiring a 4-40 UNC left-hand thread. Fits standard tap holders and collet chucks sized for this tap body diameter.

Installation Notes

This tap is installed and operated by machinists and toolroom technicians using appropriate tap holders or tapping chucks. Ensure the tap driver is aligned square to the workpiece to avoid tap breakage, particularly critical at this small diameter. Apply suitable cutting fluid for high-speed steel tooling prior to beginning the tapping cycle. Confirm spindle rotation direction is set for left-hand thread cutting before engaging the tap.