Value Collection JY4837407 8-40 Uns Hand Tap Hss Plug

Product Description

The VALUE COLLECTION JY4837407 is a straight-flute hand tap designed to cut internal threads in the 8-40 UNS thread form. Built from high speed steel with a bright uncoated finish, this tap delivers consistent thread quality in ferrous and non-ferrous materials. It features a plug chamfer with 3 to 5 lead threads, making it suitable for through-hole applications or for following a taper tap in a blind hole. With 4 flutes and an H2 thread limit, it holds tight tolerances for a Class 3B fit. Overall length is 2.125 inches. Machinists, toolroom technicians, and maintenance professionals use this tap for hand-tapping operations requiring precise thread engagement.

This tap is intended for hand-tapping applications in repair, production, and maintenance environments. The 8-40 UNS designation covers a unified national special thread form at 40 threads per inch on a Number 8 nominal diameter. Plug chamfer geometry suits both through-hole and deeper blind-hole threading where a starter tap has already been run. Right-hand cut direction aligns with standard threading technique. The H2 thread limit provides a slight oversize allowance appropriate for plated or coated fastener engagement. No coolant-through feature means this tap is used with manually applied cutting fluid or tapping compound.

Key Features

• 8-40 UNS thread form at 40 threads per inch on a Number 8 nominal diameter
• Plug chamfer with approximately 3 to 5 lead threads for through-hole and follow-up blind-hole use
• 4-flute straight flute design provides balanced cutting action and chip clearance in hand-tapping
• High speed steel construction resists heat and wear across a wide range of workpiece materials
• H2 thread limit holds Class 3B fit tolerance for precision thread engagement
• Bright uncoated finish simplifies inspection and is compatible with standard tapping fluids

Compatibility

Designed as an OEM-style replacement or standard toolroom tap for hand-tapping operations requiring an 8-40 UNS internal thread in a Class 3B fit.

Installation Notes

This tap is installed by hand using a tap wrench; power driving is not recommended without verified feed control. Before tapping, ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct tap drill size for the 8-40 thread form. Apply a suitable cutting fluid or tapping compound to reduce friction and extend tap life. Back off the tap periodically to break chips and prevent binding, particularly in deeper holes.