Hertel K008623AS Straight Flute Tap 7/8-14 Unf Hss

Product Description

The HERTEL K008623AS is a straight flute tap designed to cut right-hand internal threads to the 7/8-14 UNF standard in through-hole and blind-hole applications. Built from high-speed steel with a bright, uncoated finish, it delivers consistent thread form at a 3B class of fit with an H4 thread limit. The taper chamfer — typically 8 to 10 threads — eases entry and distributes cutting load across multiple flutes, reducing the chance of tap breakage in harder materials. With 4 flutes and a 4-11/16 inch overall length, the K008623AS is suited for production and maintenance environments where thread accuracy is required.

This tap is used in machine shops, maintenance facilities, and field service operations where 7/8-14 UNF threads are needed in ferrous and non-ferrous metals. The taper chamfer style makes it appropriate as a starting tap in new hole applications or when working with tougher materials that benefit from a gradual thread engagement. It is commonly used in manual tapping, drill press, and light CNC tapping operations where coolant-through tooling is not required.

Key Features

• 7/8-14 UNF thread form for fine-pitch internal threading applications
• Taper chamfer distributes cutting load gradually for easier entry and reduced breakage risk
• High-speed steel construction provides toughness and wear resistance across common workpiece materials
• 3B class of fit and H4 thread limit for standard tolerance internal threads
• 4-flute straight flute geometry supports chip clearing in through-hole and shallow blind-hole work
• Bright, uncoated finish — no coating buildup to affect thread tolerances

Compatibility

Designed as a standard replacement or stocking tap for any application requiring 7/8-14 UNF right-hand internal threads at a 3B class of fit. Suitable for use with standard tap wrenches, T-handle wrenches, drill press tapping attachments, and compatible CNC tapping heads that accept straight-shank taps of this size range.

Installation Notes

Secure the workpiece firmly before tapping and ensure the starting hole is drilled to the correct tap drill diameter for 7/8-14 UNF threads. Apply appropriate cutting fluid for the workpiece material to reduce heat and extend tap life. For blind holes, clear chips frequently to prevent packing and tap breakage. Coolant-through operation is not supported by this tap.