Value Collection JY4872057 Hand Tap 1-3/8-8 Uns Hss

Product Description

The VALUE COLLECTION JY4872057 is a 1-3/8-8 UNS straight flute hand tap designed for cutting internal threads in through-holes and blind holes where chip flow toward the shank is acceptable. Built from high speed steel (HSS) with a bright, uncoated finish, this tap delivers reliable cutting performance in a range of workpiece materials. The plug chamfer — ground with approximately 3 to 5 lead threads — makes it the most common choice for starting a thread in a pre-drilled hole or continuing a thread after a taper tap. With 4 flutes and a right-hand thread direction, it is sized for use with standard tapping wrenches or a tap handle in a manual threading operation.

This tap is suited for job-shop machining, maintenance and repair operations, and toolroom work where 1-3/8-8 UNS threads are required. The UNS (Unified National Special) thread standard indicates a special combination of diameter and pitch not covered by standard UNC or UNF series, making this tap appropriate when a specific thread callout on a print or assembly requires it. Machinists, toolmakers, and maintenance technicians performing manual tapping operations are the primary users. The H5 thread limit controls the tolerance of the tapped hole, producing threads on the higher end of the tolerance range to accommodate plating or tight-fit fastener requirements.

Key Features

• 1-3/8-8 UNS thread size with right-hand thread direction
• Plug chamfer for general-purpose through-hole and blind-hole tapping
• 4-flute straight flute geometry for manual tapping applications
• H5 thread limit for controlled tolerance in tapped holes
• High speed steel construction with bright, uncoated finish
• 6-1/16 inch overall length with 3 inch thread length

Compatibility

Designed for use in manual hand-tapping operations requiring a 1-3/8-8 UNS thread form; compatible with standard tap handles and tapping wrenches sized for large-diameter taps.

Installation Notes

This tap is intended for use by machinists or maintenance technicians performing manual threading operations. Secure the workpiece before tapping and ensure the pre-drilled hole diameter matches the correct tap drill size for a 1-3/8-8 UNS thread. Apply cutting fluid appropriate for the workpiece material to extend tap life and improve thread quality. Back off the tap periodically to break chips and avoid binding, and never force a tap — excessive torque can cause breakage in the hole.