Value Collection JY4874954 Hand Tap 1-9/16-18 Unef Bottoming

Product Description

The VALUE COLLECTION JY4874954 is a bottoming hand tap designed for cutting internal threads in pre-drilled holes. It produces a 1-9/16-18 UNEF right-hand thread to a Class 3B tolerance with an H4 thread limit, making it suitable for precision threading applications that require tight fits. The tap is ground from bright, uncoated high speed steel and features six straight flutes for efficient chip evacuation in through-hole and blind-hole work. Overall length is 5 inches. This tool is used by machinists and maintenance technicians working in metalworking, fabrication, and repair environments.

The bottoming chamfer design allows threading to the bottom of blind holes, which is useful in applications where full thread depth is required close to the hole floor. The 1-9/16-18 UNEF thread form is a fine-pitch specification commonly encountered in precision mechanical assemblies, instrumentation, and threaded fastener applications. This tap is suited for use in machine shops, toolrooms, and field maintenance operations where accurate internal threading of steel, aluminum, and similar materials is required.

Key Features

• Bottoming chamfer allows threading to the bottom of blind holes
• 1-9/16-18 UNEF fine-pitch thread form for precision assemblies
• Class 3B fit with H4 thread limit for tight tolerance work
• Six straight flutes for controlled chip evacuation
• High speed steel construction for hardness and wear resistance
• Bright, uncoated finish with no coolant-through feature — suited for standard tapping with applied cutting fluid

Compatibility

Designed as a standard hand tap for cutting 1-9/16-18 UNEF right-hand internal threads in metalworking and fabrication applications where a Class 3B, H4-limit bottoming tap is specified.

Installation Notes

Installation is performed by machinists or skilled maintenance technicians using a tap wrench or appropriate tapping fixture. The workpiece should be secured and the pilot hole sized to the correct tap drill diameter for a 1-9/16-18 UNEF thread before use. Apply cutting fluid throughout the tapping operation to reduce heat and extend tool life. Back the tap off periodically to break and clear chips, particularly in deep or blind holes.