Guhring 9039280028450 Hand Tap 4-40 Unc Plug Tin Hss

Product Description

The GUHRING 9039280028450 is a 4-40 UNC straight flute hand tap designed for right-hand threading in through-hole applications. Built from high speed steel with a titanium nitride (TiN) coating, this tap delivers extended wear resistance and reduced friction during the cutting process. It runs a plug chamfer for general-purpose tapping where the hole is accessible from one side. With a 2-flute straight flute geometry and a class 2B thread fit, it produces accurate internal threads that meet standard UNC tolerance requirements. Overall length is 2.205 inches, making it a compact, handleable tool for bench or machine-assisted hand tapping. It is part of the GUHRING Series 3928 and is well suited for machinists and maintenance technicians working with aluminum and similar materials.

This tap is intended for through-hole threading in 4-40 UNC applications, particularly in aluminum workpieces. The straight flute design works effectively in shorter through-holes where chip evacuation is not a significant constraint. Typical use cases include fixture fabrication, electronic enclosure assembly, and general mechanical assembly work where 4-40 fasteners are specified. The plug chamfer style requires a clear hole exit, making it most appropriate for through-hole rather than blind-hole work. This tool is used by machinists, tool and die technicians, and maintenance professionals in both production and job-shop environments.

Key Features

• TiN coating increases surface hardness and extends tool life compared to uncoated HSS
• Plug chamfer provides general-purpose entry suitable for through-hole threading
• 2-flute straight flute geometry supports chip clearance in through-hole applications
• Class 2B thread fit with H2/H3 thread limit for standard UNC tolerance compliance
• Optimized for aluminum material applications
• Part of GUHRING Series 3928 for consistent tooling standardization

Compatibility

Designed for 4-40 UNC through-hole threading applications, particularly in aluminum. Thread limit H2/H3 makes this tap compatible with standard 2B class fit fastener assemblies per UNC specification.

Installation Notes

This tap is installed using a standard tap wrench or T-handle for hand tapping. Ensure the workpiece is securely clamped and the pilot hole is drilled to the correct tap drill diameter for 4-40 UNC before beginning. Apply appropriate cutting fluid for aluminum to reduce built-up edge and extend tap life. Do not force the tap against resistance - back off periodically to break chips and prevent tap breakage.