Kennametal 4131320 Hand Tap 5/16-18 Unc Bottoming Hss

Product Description

The KENNAMETAL 4131320 is a straight-flute hand tap designed for cutting internal threads in pre-drilled holes. Built from high-speed steel (HSS) with a bright, uncoated finish, it cuts right-hand threads to a 5/16-18 UNC specification with a Class 3B fit and H3 thread limit. The bottoming chamfer allows threading to the bottom of blind holes where a plug or taper tap cannot reach. Overall length is 2.72 inches with a thread length of 1.125 inches and a shank diameter of 0.318 inches. Machinists and tool-and-die professionals use this tap for precision threading in production and maintenance environments.

This tap is suited for threading cast iron and non-ferrous metals. The bottoming chamfer style makes it the final tap in a threading sequence for blind holes, typically following a taper or plug tap to open the thread before the bottoming tap finishes to full depth. It is used in manual hand-tapping applications. The 3-flute straight-flute configuration provides good chip clearance and thread form consistency across the supported material applications.

Key Features

• Bottoming chamfer for threading to the bottom of blind holes
• High-speed steel construction for durability in cast iron and non-ferrous metal
• Bright, uncoated finish with no additional coating - ready for use or operator-applied lubricant
• 3-flute straight-flute design for consistent chip evacuation and thread form
• Class 3B fit with H3 thread limit for tight tolerance threading
• Right-hand thread direction, 5/16-18 UNC

Compatibility

Belongs to KENNAMETAL Series 5305 and 5303. Designed for use in cast iron and non-ferrous metal workpieces requiring 5/16-18 UNC internal threads.

Installation Notes

This tap is intended for hand-tapping operations using a tap wrench or T-handle. Always use cutting fluid or tapping lubricant appropriate for the workpiece material to extend tap life and improve thread quality. Ensure the tap enters the hole square to avoid thread damage or tap breakage. Follow standard machining safety practices and secure the workpiece before starting.