Value Collection MSC-04918157 Straight Flute Tap 7/8-14 Unf

Product Description

The VALUE COLLECTION MSC-04918157 is a straight flute bottoming tap designed for cutting 7/8-14 UNF left-hand internal threads. Built from high-speed steel with a bright/uncoated finish, this tap is engineered for threading operations that require full-depth engagement close to the bottom of a blind hole. The bottoming chamfer provides only 1-2 threads of lead-in, making it the right choice when thread engagement must start at or near the bottom of the bore. With 4 flutes and an H4 thread limit, it delivers consistent sizing and chip clearance for production and maintenance threading work.

This tap is suited for machinists, tool-and-die makers, and maintenance technicians working with ferrous and non-ferrous materials where a left-hand 7/8-14 UNF thread form is required. Left-hand taps are typically used in applications where standard right-hand threads would loosen under rotational load, such as certain spindle assemblies, turnbuckles, and specialized fastener applications. The 4-flute straight design works best in through-hole or moderately shallow blind-hole applications with good chip evacuation.

Key Features

• Bottoming chamfer for threading to the base of blind holes
• Left-hand thread direction for counter-rotation fastening applications
• High-speed steel construction for durability across a range of workpiece materials
• H4 thread limit for controlled oversize tolerance and consistent fit
• 3B class of fit for standard internal thread tolerance
• Bright/uncoated finish suitable for use with cutting fluid

Compatibility

Designed as an OEM-style replacement or direct-use tap for applications requiring a 7/8-14 UNF left-hand internal thread with a 3B class of fit.

Installation Notes

This tap should be installed and operated by a qualified machinist familiar with tapping speeds, cutting fluids, and proper tap alignment. Always secure the workpiece and ensure the tap is started square to the hole to prevent breakage. Use an appropriate cutting fluid for the workpiece material to extend tool life and improve thread finish. Never force a bottoming tap into a hole that has not been pre-threaded with a taper or plug tap first.