Value Collection JY4837415 Hand Tap 8-40 Uns Bottoming Hss

Product Description

The VALUE COLLECTION JY4837415 is a straight-flute hand tap designed to cut 8-40 UNS internal threads in a bottoming chamfer configuration. Built from high speed steel with a bright, uncoated finish, this tap is suited for threading holes to the bottom of a blind bore. It carries a Class 3B fit designation and an H2 thread limit, making it appropriate for close-tolerance tapping applications. Overall length is 2-1/8 inches. With 4 flutes and a right-hand thread direction, it is intended for use in manual tapping operations by machinists, maintenance technicians, and trade professionals working in metal fabrication, repair, or assembly.

This tap is used when a standard chamfer tap has already started the thread and a fully threaded blind hole is required. The bottoming chamfer leaves only 1 to 2 incomplete threads at the bottom of the hole, maximizing usable thread depth. It is appropriate for light-duty metals in both shop and field maintenance settings. The UNS thread standard applies to specialized thread forms not covered by standard UNC or UNF series, making this tap relevant for replacement fastener work, industrial repair, and legacy equipment maintenance.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• High speed steel construction for durability across a range of metals
• Bright, uncoated finish suited for general-purpose tapping
• 4-flute straight flute design for controlled chip handling in manual use
• Class 3B fit and H2 thread limit for close-tolerance thread production
• Right-hand thread direction for standard clockwise cutting

Compatibility

Designed as an OEM-style replacement or standard tooling option for manual tapping of 8-40 UNS right-hand internal threads in blind or through holes requiring a bottoming chamfer profile.

Installation Notes

Installation is performed by machinists and maintenance technicians using a standard tap wrench or tee-handle. The workpiece should be secured before tapping begins, and proper cutting fluid should be applied to reduce friction and improve thread quality. Follow the hole with a taper or plug tap first to establish the thread before using this bottoming tap. Inspect the tap for wear or chipping before each use, as a damaged tap can seize in the hole or produce out-of-tolerance threads.