Hertel K033018AS Spiral Flute Tap 3/8-16 Unc Hss Oxide

Product Description

The HERTEL K033018AS is a spiral flute tap designed for cutting internal threads in through-holes and blind holes where chip evacuation is a priority. Built from high-speed steel with an oxide coating, it produces 3/8-16 UNC right-hand threads to a 3B class of fit with an H3 thread limit. The 45-degree helix angle drives chips up and out of the hole during cutting, reducing the risk of clogging in deeper features. At 2-15/16 inches overall length, this plug chamfer tap is suited for general-purpose tapping on manual machines and CNC machining centers alike. Machinists, tool-and-die makers, and maintenance technicians are the primary users.

This tap is used in ferrous and non-ferrous materials where a spiral flute geometry outperforms straight flutes by pulling chips out of the hole rather than packing them. The plug chamfer provides a gradual lead-in, making it appropriate for through-holes and shallow blind holes. It is commonly found in production tapping, maintenance and repair operations, and job-shop environments requiring consistent 3/8-16 UNC thread quality. The 3B class of fit is the standard tolerance class for most general mechanical assemblies using inch-series unified threads.

Key Features

• 3/8-16 UNC thread form, right-hand direction, 3B class of fit
• H3 thread limit for controlled oversize tolerance
• 45-degree helix angle for fast, effective chip evacuation in through-holes
• Plug chamfer for gradual lead-in and versatile hole-type compatibility
• High-speed steel construction with oxide coating for lubricity and mild corrosion resistance
• 2-15/16 inches overall length for standard spindle reach

Compatibility

Designed as an OEM-style replacement or direct-use tap for any manual or CNC tapping application requiring 3/8-16 UNC internal threads to a 3B class of fit.

Installation Notes

Installation should be performed by a qualified machinist following standard tapping procedures. Secure the workpiece and ensure the tap is properly aligned to the drilled pilot hole before engaging the spindle or tap wrench. Apply cutting fluid appropriate to the workpiece material to extend tap life and improve thread quality. Inspect the tap for wear or chipping before each use and replace if cutting edges are degraded.