Emuge BU51C410.5609 Spiral Flute Sti Tap 2-56 Unc Hss

Product Description

The EMUGE BU51C410.5609 is a high speed steel spiral flute STI tap designed for cutting Screw Thread Insert threads in 2-56 UNC applications. It features a 4-flute, 45-degree right-hand helix geometry with a bottoming chamfer, making it suited for threading operations that require full thread depth close to the bottom of a blind hole. The GLT-1 surface finish improves chip evacuation and reduces galling during tapping. At 1.772 inches overall length with a 0.141-inch shank diameter and 0.276-inch thread length, this tap fits standard tap holders used in precision machining environments. It belongs to the EMUGE Enorm Z/E series, engineered for demanding thread quality requirements.

This tap is intended for use in alloy steel and stainless steel workpieces where STI threads are required to accept threaded inserts at the 2-56 UNC pitch. The bottoming chamfer allows threading to within 1-2 thread pitches of a blind hole bottom, making it a practical choice for close-tolerance insert installations on small fastener assemblies. Machinists and toolroom technicians working in aerospace, medical device, and precision instrument applications will find this tap suited to tightly toleranced 3B class of fit requirements. It is used in both CNC tapping centers and manual tapping operations with appropriate feed control.

Key Features

• 2-56 UNC thread form, 56 threads per inch, for fine-pitch small-diameter STI applications
• 4-flute, 45-degree right-hand helix promotes upward chip flow out of the hole during tapping
• Bottoming chamfer enables threading close to the base of blind holes
• GLT-1 finish reduces friction and extends tool life in stainless steel and alloy steel
• 3B class of fit for precision thread tolerance requirements
• High speed steel construction provides toughness and regrindability

Compatibility

Designed for cutting STI threads in alloy steel and stainless steel materials at 2-56 UNC pitch. Part of the EMUGE Enorm Z/E series. Compatible with standard tap holders accepting a 0.141-inch shank diameter.

Installation Notes

Installation of this tap should be performed by a qualified machinist following established tapping procedures. The workpiece must be securely fixtured and the spindle brought to a full stop before tap engagement or removal. Use appropriate tapping fluid for stainless steel or alloy steel to reduce heat buildup and tool wear. When tapping blind holes, confirm hole depth provides sufficient clearance beyond the required thread length before starting the operation.