Value Collection MSC-04472171 3/8-16 Unc Bottoming Tap Hss

Product Description

The VALUE COLLECTION MSC-04472171 is a straight flute bottoming tap designed to cut 3/8-16 UNC internal threads in through-holes and blind holes where threads must extend close to the bottom. Made from high-speed steel with a bright uncoated finish, this tap provides reliable performance across a range of common shop materials. With 4 flutes and an H3 thread limit, it holds tight tolerances for a 3B class of fit. Overall length is 2-15/16 inches with a thread length of 1-1/4 inches. Machinists, tool-and-die workers, and general maintenance technicians use this tap for manual and machine tapping operations in production and repair environments.

This tap is suited for threading operations in ferrous and non-ferrous metals, plastics, and similar materials where a standard UNC thread form is required. The bottoming chamfer — typically 1 to 2 threads of lead — makes it the correct choice when full threads are needed to the bottom of a blind hole. It is commonly used as the finishing tap in a sequence following a taper or plug tap, or as a standalone tool in through-hole applications where thread depth is critical.

Key Features

• 3/8-16 UNC thread form for standard unified coarse-pitch threading
• Bottoming chamfer allows thread cutting to the base of blind holes
• 4 straight flutes provide strength and chip clearance in short-chipping materials
• H3 thread limit maintains accurate 3B class of fit tolerances
• High-speed steel construction withstands heat generated during tapping
• Right-hand thread direction; compatible with standard tap handles and tapping heads

Compatibility

Designed as a standard 3/8-16 UNC bottoming tap for use in manual tap wrenches, machine tap holders, and tapping attachments configured for straight shank tools of this size class.

Installation Notes

Secure the workpiece firmly before tapping and ensure the hole is drilled to the correct tap drill diameter for 3/8-16 UNC prior to use. Apply cutting fluid appropriate to the workpiece material to reduce friction and extend tap life. When tapping blind holes, clear chips frequently to prevent tap breakage. Always use a tap wrench or holder that keeps the tap aligned perpendicular to the workpiece surface.