Kennametal 4131106 Spiral Flute Tap 5/16-24 Unf Bottoming H3

Product Description

The KENNAMETAL 4131106 is a spiral flute bottoming tap designed for threading 5/16-24 UNF holes in non-ferrous metals. Built from vanadium high speed steel with a straw finish coating, it produces clean internal threads in blind holes where full thread engagement to the bottom of the bore is required. The fast-helix flute design at 52 degrees efficiently evacuates chips up and out of the hole during the tapping cycle. The H3 thread limit holds tight tolerance control for a 3B class of fit, making this tap well-suited for precision thread work in production and maintenance applications.

This tap is used in machining, metalworking, and maintenance-repair-overhaul applications where 5/16-24 UNF threads are needed close to the bottom of a blind hole. The bottoming chamfer configuration provides only 1 to 2 lead threads, maximizing usable thread depth. Typical installation scenarios include aerospace component repair, automotive parts machining, and general fabrication work involving non-ferrous materials such as aluminum and brass. A licensed machinist or toolroom technician would typically apply this tap in a tapping head, CNC machine, or hand-tapping setup.

Key Features

• Bottoming chamfer for maximum thread depth in blind holes
• 52-degree fast-helix spiral flute for efficient chip evacuation
• H3 thread limit for consistent 3B class of fit tolerance control
• Straw finish coating provides mild lubricity and heat indication during cutting
• Optimized for non-ferrous metal applications
• Right-hand thread direction, right-hand flute spiral

Compatibility

Designed for cutting 5/16-24 UNF internal threads in non-ferrous metals. Fits standard 5/16-inch tapping chucks and collets accepting a 0.318-inch shank diameter.

Installation Notes

This tap should be installed by a qualified machinist or toolroom technician familiar with thread-cutting operations. Always secure the workpiece and ensure the tapping fixture or machine spindle is properly aligned before engaging the tap to prevent tap breakage or thread distortion. Use an appropriate cutting fluid or tapping compound rated for the workpiece material to extend tool life and improve thread finish. Inspect the tap for wear or chipping before each use and replace when thread quality degrades.