Value Collection MSC-04471199 Straight Flute Tap 5/16-18 Unc

Product Description

The VALUE COLLECTION MSC-04471199 is a straight flute bottoming tap designed to cut internal threads in pre-drilled holes where full thread depth close to the bottom of a blind hole is required. Built from high-speed steel with a bright/uncoated finish, this tap cuts a 5/16-18 UNC right-hand thread to a 3B class of fit with an H3 thread limit. Four straight flutes provide clean chip evacuation in through-hole and shallow blind-hole applications. With a thread length of 1-1/8 inches and an overall length of 2-23/32 inches, it fits standard tap handles and machine tap holders used in general machining and maintenance work.

This tap is suited for threading mild steel, aluminum, brass, and similar machinable materials in job shop, maintenance, and repair environments. The bottoming chamfer — typically 1 to 2 threads of lead — allows threading to within a few threads of the bottom of a blind hole, making it the correct choice when a plug or taper tap has already started the thread and full depth is needed. It is commonly used by machinists, maintenance technicians, and fabricators working on fastener repairs, fixture builds, and production threading operations.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• 5/16-18 UNC thread form with 3B class of fit for standard fastener tolerance
• H3 thread limit for consistent fit with commercial-grade fasteners
• High-speed steel construction provides durability across a range of machinable materials
• Four straight flutes for chip clearance in through-hole and shallow blind-hole use
• Bright/uncoated finish — no coating buildup risk during regrinding or inspection

Compatibility

Designed as a standard replacement or supplemental bottoming tap for any setup requiring 5/16-18 UNC internal threads. Fits tap handles and machine holders sized for the corresponding tap shank diameter.

Installation Notes

This tap is installed by a machinist or maintenance technician using a tap wrench, T-handle, or machine tap holder. Always ensure the workpiece is secured before tapping, and apply cutting fluid appropriate to the workpiece material to extend tap life and improve thread quality. When using a bottoming tap in a blind hole, a plug tap should be used first to establish the thread, with the bottoming tap used last to extend depth. Do not force the tap if resistance increases sharply — back off to clear chips and prevent breakage.