Value Collection JY4878997 Hand Tap 2-4-1/2 Unc 6-flute Hss

Product Description

The VALUE COLLECTION JY4878997 is a 2-4-1/2 UNC straight-flute hand tap designed for cutting internal threads in large-diameter through-holes and blind-hole applications. Built from bright-finish high speed steel, this plug-chamfer tap provides the cutting geometry needed to thread tough ferrous and non-ferrous materials by hand or with a tap wrench. At 8 inches overall length, the extra reach makes it practical for deep or obstructed workpiece access. The 6-flute design distributes cutting load across more edges, reducing stress per flute and extending tool life in production tapping scenarios. Thread fit is Class 3B with an H6 thread limit, targeting close-tolerance assemblies where thread accuracy is critical.

This tap is intended for machinists, tool-and-die makers, maintenance technicians, and pipefitters working with large-format fasteners in the 2-inch nominal diameter range. The plug chamfer — typically 3 to 5 threads of lead — makes it the standard choice for through-hole tapping and for following a taper tap in blind-hole sequences. Right-hand thread direction is consistent with standard UNC fastener systems used across industrial, structural, and heavy-equipment applications.

Key Features

• 2-4-1/2 UNC thread form for large-diameter internal threading
• Plug chamfer geometry suited for through-hole and follow-up blind-hole tapping
• 6 straight flutes distribute cutting force and improve tool longevity
• High speed steel construction handles ferrous and non-ferrous workpiece materials
• Bright uncoated finish for easy visual wear inspection
• Class 3B fit with H6 thread limit for close-tolerance thread accuracy

Compatibility

Designed for use with standard tap wrenches and tap handles sized for large-diameter taps; compatible with any setup requiring a 2-4-1/2 UNC Class 3B right-hand internal thread.

Installation Notes

This tap is installed by licensed machinists or qualified maintenance technicians using a properly sized tap wrench or machine tap holder. Secure the workpiece firmly before tapping and ensure the tap is started square to the hole to prevent thread crosstie or tap breakage. Apply appropriate cutting fluid for the workpiece material throughout the tapping operation. Back the tap out periodically to clear chips, particularly in deeper holes.