Kennametal 4131019 Spiral Flute Tap 3/8-16 Unc Bottoming 3B

Product Description

The KENNAMETAL 4131019 is a spiral flute bottoming tap designed for cutting internal threads in a wide range of materials. It features a 3/8-16 UNC thread form with a 3B class of fit, making it suitable for standard-tolerance threaded connections in production and maintenance environments. Constructed from vanadium high speed steel with a TiN (titanium nitride) coating, the tap offers improved wear resistance and lubricity compared to uncoated tooling. With a 52-degree helix angle and fast-flute geometry, it efficiently evacuates chips upward through the flute — a key advantage when tapping blind holes. Licensed machinists, tool-and-die makers, and CNC operators are the primary users.

This tap is suited for both manual and machine tapping operations. The bottoming chamfer (1-2 thread lead) allows threading close to the bottom of blind holes where a plug or taper tap cannot reach. Its material application range spans aluminum, cast iron, non-ferrous metals, stainless steel, and steel, making it a versatile tool for job shops, maintenance facilities, and production lines. The right-hand thread direction and right-hand flute direction match standard tapping setups without requiring special toolholding.

Key Features

• 3/8-16 UNC thread form with 3B class of fit for standard-tolerance internal threads
• Bottoming chamfer allows threading to the bottom of blind holes
• 52-degree helix angle with fast-flute geometry for efficient upward chip evacuation
• TiN coating improves surface hardness and reduces friction during cutting
• Compatible with aluminum, cast iron, non-ferrous metals, stainless steel, and steel
• No coolant-through feature — suited for conventional flood or manual lubrication

Compatibility

Designed for use in applications requiring 3/8-16 UNC internal threads with a 3B class of fit across aluminum, cast iron, non-ferrous metal, stainless steel, and steel workpieces.

Installation Notes

Installation should be performed by a qualified machinist or tooling technician using a properly aligned tap holder or tapping head to prevent tap breakage. Ensure the workpiece is securely fixtured and the pilot hole diameter matches the correct tap drill size for 3/8-16 UNC before beginning. Apply appropriate cutting fluid or tapping compound for the workpiece material — especially critical when tapping stainless steel. Follow shop safety protocols and machine guarding requirements during all tapping operations.