Value Collection MSC-04912259 Straight Flute Tap 3/8-24 Unf

Product Description

The VALUE COLLECTION MSC-04912259 is a straight flute bottoming tap designed to cut internal threads in pre-drilled holes where full thread engagement near the bottom of a blind hole is required. Manufactured from high-speed steel with a bright/uncoated finish, this tap produces a 3/8-24 UNF left-hand thread to a 3B class of fit with an H3 thread limit. It features 4 flutes and a 1.25-inch thread length within an overall length of 2.9375 inches. Machinists, toolmakers, and maintenance mechanics use this tap for precision threading operations on ferrous and non-ferrous materials where standard tapping torque limits apply.

This bottoming tap is suited for applications where a thread must run as close to the bottom of a blind hole as possible. The left-hand thread direction makes it the correct choice for components that must resist loosening under counterclockwise rotation loads, such as left-hand threaded fastener inserts, fixtures, and specialty machine components. It is used in manual tapping operations as well as low-speed machine tapping setups where proper alignment and controlled feed rate are maintained.

Key Features

• 3/8-24 UNF thread form with left-hand thread direction for counterclockwise thread applications
• Bottoming chamfer allows threading to within 1-2 thread pitches of the bottom of a blind hole
• 3B class of fit with H3 thread limit provides standard tolerance threading for general precision work
• 4-flute straight flute geometry suitable for tapping shorter-chipping materials
• High-speed steel construction offers reliable performance across a range of common workpiece materials
• Bright/uncoated finish — no coating buildup to affect thread form dimensions

Compatibility

Designed as a standard replacement or production tap for any application requiring a 3/8-24 UNF left-hand internal thread to a 3B class of fit. Compatible with standard tap wrenches, T-handle tap holders, and machine tap holders that accept the corresponding shank diameter for this tap size.

Installation Notes

This tap is installed and operated by a machinist or maintenance mechanic using a tap wrench or appropriate machine holder. Ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct tap drill diameter for a 3/8-24 UNF thread before tapping. Apply cutting fluid appropriate for the workpiece material to reduce heat and extend tap life. For blind holes, count flute passes carefully to avoid bottoming the tap under load, which can cause breakage.