Value Collection MSC-04488102 7/8-9 Unc Bottoming Tap Hss

Product Description

The VALUE COLLECTION MSC-04488102 is a straight flute bottoming tap designed for cutting internal threads in through-holes and blind holes where full thread depth close to the bottom is required. Made from high-speed steel with a bright uncoated finish, this tap produces a 7/8-9 UNC right-hand thread to a 3B class of fit. The H4 thread limit ensures dimensional consistency suitable for standard tolerance applications. With a thread length of 2-7/32 inches and an overall length of 4-11/16 inches, it is sized for typical production and maintenance threading operations. Machinists, tool-and-die makers, and maintenance technicians use this tap in drill presses, CNC machines, and manual tapping setups.

This tap is suited for threading steel, cast iron, aluminum, and similar materials in general manufacturing, maintenance, and repair environments. The bottoming chamfer — typically 1 to 2 thread leads — allows the tap to cut threads nearly to the bottom of a blind hole, making it the correct choice when a plug or taper tap has already started the thread and full thread engagement to the floor of the hole is needed. It is commonly used in fabrication shops, machine shops, and industrial maintenance settings where 7/8-9 UNC fastener holes are required.

Key Features

• 7/8-9 UNC thread form with right-hand direction for standard inch-series fastener holes
• Bottoming chamfer for full thread depth in blind holes
• 3B class of fit for standard tolerance threaded assemblies
• H4 thread limit for consistent dimensional accuracy
• High-speed steel construction for durability across a range of workpiece materials
• Bright uncoated finish — no coating buildup to affect thread tolerance
• 4 straight flutes for chip clearance in through-hole and short blind-hole applications

Compatibility

Designed as a standard replacement or production bottoming tap for 7/8-9 UNC threaded hole applications across general machining, fabrication, and industrial maintenance operations.

Installation Notes

This tap should be installed in a compatible tap holder, floating tap chuck, or rigid tapping setup rated for the shank size. Always ensure the workpiece is securely fixtured and the tap is properly aligned with the drilled hole before engagement to prevent breakage. For manual use, apply appropriate cutting fluid to reduce heat and extend tap life. Follow your facility safety procedures and power down any machine before changing tooling.