Hertel K008100AS Straight Flute Tap 4-48 Unf Taper Hss

Product Description

The HERTEL K008100AS is a straight flute tap designed to cut 4-48 UNF internal threads in a single-pass tapping operation. Built from high-speed steel with a bright, uncoated finish, this tap delivers consistent thread geometry across a wide range of ferrous and non-ferrous materials. It features a taper chamfer for easy thread entry and a 2B class of fit, which meets standard tolerance requirements for most threaded fastener assemblies. The right-hand thread direction and H2 thread limit keep dimensional control tight. Overall length is 1.875 inches, and the tool weighs approximately 0.1 pounds. Machinists, tool-and-die workers, and maintenance technicians use this tap for hand or machine tapping where fine unified threads are required.

The K008100AS is suited for light to medium threading work on small-diameter holes calling for a 4-48 UNF thread form. The taper chamfer style distributes cutting load across several leading threads, making it well-suited for through-hole applications and for starting threads in blind holes where a bottoming tap is not yet needed. Typical applications include instrument components, precision assemblies, and small fastener repair work where the 4-48 fine thread provides greater holding strength than a coarse-thread equivalent of the same nominal diameter.

Key Features

• 4-48 UNF thread size with taper chamfer for smooth thread entry and distributed cutting load
• 2B class of fit meets standard tolerance requirements for general-purpose threaded assemblies
• H2 thread limit for controlled dimensional accuracy
• 3 straight flutes for chip clearance in through-hole and short blind-hole applications
• High-speed steel construction handles a broad range of workpiece materials
• Bright, uncoated finish — no coating thickness variation affecting thread tolerance

Compatibility

Designed as a standard replacement or general-use straight flute tap for 4-48 UNF threading operations in hand-tapping fixtures, drill presses, tapping heads, and CNC machines equipped with a tap holder of the appropriate shank size.

Installation Notes

This tap is installed by a machinist or tool-and-die technician using a tap wrench, tapping head, or rigid machine holder sized to the shank. Ensure the workpiece is securely fixtured and the pilot hole diameter is correctly sized for a 4-48 UNF thread before beginning. Apply appropriate cutting fluid to reduce heat and extend tool life, particularly in ferrous materials. Inspect flutes for chips or damage before each use and replace the tap if cutting edges show signs of wear to avoid thread form degradation.