Value Collection MSC-04911251 Hand Tap 5/16-24 Unf

Product Description

The VALUE COLLECTION MSC-04911251 is a 5/16-24 UNF bottoming hand tap ground from high speed steel with a bright uncoated finish. It is designed for cutting left-hand internal threads in through-holes and blind holes where threads must extend close to the bottom. The bottoming chamfer — typically 1 to 2 threads of lead — allows the tap to thread nearly to the full depth of a blind hole. With 4 straight flutes, this tap is suited for use in a tap wrench by hand. Machinists, toolmakers, and maintenance technicians use this style of tap as the final pass in a 3-tap set or as a standalone tool when access and depth require it.

This tap is intended for general threading operations in ferrous and non-ferrous metals where a Class 3B fit and a left-hand thread direction are required. Left-hand taps are commonly used when standard right-hand threads would loosen under rotational load, such as on left-side spindle assemblies, bicycle components, and certain mechanical fastener applications. The straight-flute design works best in through-holes or short blind holes where chip management is handled manually. It is appropriate for low-volume hand-tapping in job shop, maintenance, and repair environments.

Key Features

• Bottoming chamfer allows threading to near full depth in blind holes
• Left-hand thread direction for applications requiring reverse-thread fastening
• 4 straight flutes provide stability and chip clearance during hand tapping
• High speed steel construction offers good wear resistance for general metalworking
• Bright uncoated finish — no coating buildup to affect thread tolerances
• Class 3B fit with H3 thread limit for close-tolerance internal threads

Compatibility

Designed as an OEM-style replacement or standard shop tap for any application requiring a 5/16-24 UNF left-hand internal thread at a Class 3B fit.

Installation Notes

This tap is installed by hand using a standard tap wrench — power tapping is not recommended for left-hand taps without a dedicated reverse-spindle setup. Always secure the workpiece firmly before tapping and apply a suitable cutting fluid to extend tool life and improve thread finish. Back the tap off periodically to break chips, especially in deeper holes. Follow applicable shop safety practices for rotating and sharp cutting tools.