Hertel K033029AS Spiral Flute Tap 1/2-20 Unf Bottoming Hss

Product Description

The HERTEL K033029AS is a spiral flute tap designed to cut 1/2-20 UNF internal threads in blind-hole applications. Built from high-speed steel with an oxide coating, it runs 3 right-hand flutes at a 45-degree helix angle to evacuate chips efficiently during the tapping cycle. The bottoming chamfer allows threading to the bottom of a blind hole, making it the correct choice when full thread depth close to the hole floor is required. Overall length is 3.375 inches. This tap is used by machinists and maintenance technicians working on precision threaded assemblies where UNF thread standards and tight tolerance fits are specified.

The K033029AS is suited for production and repair threading operations in manufacturing, maintenance, and toolroom environments. The 3B class of fit produces a standard-tolerance internal thread compatible with general-purpose UNF fastener assemblies. The fast flute style and 45-degree helix angle make this tap effective in materials that produce stringy or continuous chips, including many steels and aluminum alloys. A coolant-through feature is not included, so flood or brush-applied cutting fluid should be used at the spindle to extend tool life.

Key Features

• Bottoming chamfer for threading to the bottom of blind holes
• 45-degree helix angle with fast flute style for efficient chip evacuation
• High-speed steel construction for wear resistance across a range of workpiece materials
• Oxide coating reduces friction and improves lubricity during the cut
• H3 thread limit for consistent 3B class of fit tolerance control
• Right-hand thread and right-hand flute direction for standard CNC and manual spindle use

Compatibility

Designed as an OEM-style tooling replacement for 1/2-20 UNF bottoming tap applications requiring a 3B class of fit in right-hand threaded blind holes.

Installation Notes

This tap is installed in a tap holder, tapping head, or rigid CNC toolholder by a machinist or toolroom technician. Always ensure the workpiece is securely fixtured and the tap is properly aligned to the pilot hole before beginning the tapping cycle. Apply cutting fluid appropriate to the workpiece material to prevent galling and extend tool life. Inspect the tap for chipping or wear before each use, and replace it if cutting edges show damage to avoid thread quality issues or tap breakage in the hole.