Emuge BU591410.5043 Thread Forming Tap 1/4-28 Unf Bottoming

Product Description

The EMUGE BU591410.5043 is a thread forming tap designed for producing internal threads in blind hole applications without generating chips. Sold under the InnoForm 1-MULTI/E-SN-TiN trade name, this tap is manufactured from High-Speed Steel-E (HSS-E) and coated with Titanium Nitride (TiN) for improved wear resistance and tool life. It cuts a 1/4-28 UNF right-hand thread to a 3BX class of fit and features a bottoming chamfer with 1.5 to 2 chamfered threads, allowing threading close to the bottom of a blind hole. Overall length is 3.1496 inches. Licensed machinists, tool-and-die makers, and maintenance technicians use this tap in production and repair environments.

This tap is suited for blind hole threading in steel, stainless steel, and non-ferrous metals, covering material application codes P, M, and N. The bottoming chamfer geometry is particularly useful when thread depth must be maximized in shallow blind holes. A tapping depth of 0.1811 inches and a thread length of 0.6693 inches make it appropriate for compact fastener bosses common in precision machined components, automotive assemblies, and structural fabrications. The 3xD flute-by-diameter ratio supports stable tool engagement across these material groups.

Key Features

• Thread forming (chipless) design eliminates chip evacuation concerns in blind holes
• High-Speed Steel-E construction provides toughness for interrupted cuts and harder alloys
• Titanium Nitride coating reduces friction and extends tool life across material types
• Bottoming chamfer (1.5 to 2P) threads to near full depth in blind holes
• 3BX class of fit suits tight-tolerance threaded fastener applications
• Right-hand 1/4-28 UNF thread form compatible with unified fine-thread fastener systems

Compatibility

Designed for blind hole threading in steel, stainless steel, and non-ferrous metals (material application codes P, M, N). Suitable for use with standard 1/4-28 UNF tapping fixtures and CNC or manual tapping machines accepting a 0.2550-inch shank diameter with a 0.1910-inch square drive.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which differs from cutting tap drill sizes - consult a thread forming drill chart for the correct pre-drill diameter before use. Secure the workpiece and use appropriate tapping fluid or cutting oil suited to the workpiece material to protect both the tap and the finished thread. Power down or de-energize any CNC machine before manually loading or unloading the tap. This tap does not produce chips but does displace material, so ensure the base material has adequate ductility before use in hardened or brittle substrates.