Value Collection JY4842407 Straight Flute Tap 3/8-40

Product Description

The VALUE COLLECTION JY4842407 is a straight flute plug tap designed for cutting right-hand internal threads in a 3/8-40 UNS thread profile. Manufactured from high-speed steel with a bright, uncoated finish, this tap is suited for general-purpose threading operations in a machine shop or maintenance environment. The plug chamfer — typically 3 to 5 threads — makes it the standard choice for through-hole threading and most blind-hole applications where thread engagement can start with a gradual lead-in. With 4 flutes and an H2 thread limit, it holds tight dimensional tolerances appropriate for close-fit fastener assemblies.

This tap is used in production and maintenance machining where UNS (Unified National Special) thread forms are required at 3/8 inch diameter and 40 threads per inch. The UNS designation indicates a non-standard pitch for this diameter, making this tap a specialty tool rather than a general catalog size. Typical applications include instrument housings, fluid fittings, and mechanical assemblies where a finer-than-standard thread is specified by the engineering drawing. It is intended for use by machinists, toolmakers, and maintenance technicians working on manual or CNC tapping equipment.

Key Features

• 3/8-40 UNS thread profile — specialty pitch at 40 threads per inch for fine-thread fastener applications
• Plug chamfer provides a gradual lead-in, ideal for through-holes and most standard blind-hole depths
• 4 straight flutes suitable for use in short-chipping materials such as cast iron and brass
• H2 thread limit for controlled tolerance fit in close-tolerance assemblies
• High-speed steel construction offers good wear resistance at moderate cutting speeds
• Bright, uncoated finish — compatible with standard cutting oils and tapping fluids

Compatibility

Designed as a straight flute plug tap for use wherever a 3/8-40 UNS right-hand internal thread is specified. No specific equipment or model compatibility was provided by the manufacturer for this part.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician using a properly aligned tapping head, tap handle, or CNC tapping cycle. Always apply an appropriate cutting fluid or tapping compound for the workpiece material to extend tool life and improve thread finish. Secure the workpiece firmly and ensure the tap enters the hole square to the axis. Never force a tap against bottom in a blind hole without verifying available thread depth, as this can result in tap breakage.