Hertel K008095AS Spiral Flute Tap 4-40 Unc Hss

Product Description

The HERTEL K008095AS is a spiral flute tap designed for threading 4-40 UNC fastener holes in metal workpieces. It features a 2-flute, right-hand spiral design with a 52-degree helix angle that evacuates chips upward out of blind holes, reducing the risk of chip packing and tap breakage. The plug chamfer provides a standard lead-in suitable for through holes and shallow blind holes. Manufactured from high-speed steel, it is rated for Class of Fit 2B/3B and carries a Thread Limit of H2. Overall length is 1.875 inches. This tap is a standard production tool used by machinists, tool-and-die makers, and maintenance technicians across general manufacturing and repair applications.

The K008095AS is suited for tapping 4-40 UNC threads in ferrous and non-ferrous materials where spiral flute geometry is preferred over standard hand-tap fluting. The fast flute style and 52-degree helix angle make it especially effective in blind-hole applications where chip clearance is critical. It is a common choice for small-screw assembly work in electronics enclosures, instrument panels, and light mechanical assemblies where 4-40 UNC is the specified thread standard.

Key Features

• 4-40 UNC thread form, right-hand thread direction
• 52-degree helix angle with fast flute style for efficient chip evacuation in blind holes
• Plug chamfer for standard lead-in on through holes and shallow blind holes
• High-speed steel construction for durability across common machining materials
• Thread Limit H2, Class of Fit 2B/3B for standard tolerance threading
• No coolant-through configuration - suitable for hand or low-speed machine tapping with applied cutting fluid

Compatibility

Designed as a standard 4-40 UNC spiral flute plug tap for use in tapping heads, tap handles, or CNC and manual drilling machines configured for small-diameter threading operations.

Installation Notes

This tap is installed by machinists and maintenance technicians using a standard tap wrench, tapping head, or CNC rigid-tapping spindle. Ensure the correct 4-40 UNC tap drill diameter is used in the workpiece before tapping. Apply appropriate cutting fluid for the workpiece material to extend tap life and improve thread finish. Secure the workpiece fully before beginning the tapping operation to prevent tap deflection or breakage.