Hertel K008944AS Tap Set 1-1/8-7 Unc 4 Flute Hss

Product Description

The HERTEL K008944AS is a 3-piece tap set designed to cut 1-1/8-7 UNC internal threads in metal workpieces. Built from high speed steel with a bright finish, this set delivers the hardness and wear resistance required for production and maintenance threading applications. The 4-flute geometry provides stable cutting action and efficient chip evacuation in through-hole and blind-hole configurations. With an overall length of 5.4375 inches and a thread length of 2.5625 inches, the set handles standard depth requirements for this thread size. The H4 thread limit ensures consistent fit within 2B and 3B class-of-fit tolerances, making it suitable for general-purpose and close-tolerance fastener applications.

This tap set is used in machine shops, industrial maintenance facilities, and fabrication environments where large-diameter UNC threads are required. Right-hand thread direction makes it compatible with standard tapping heads, CNC machining centers, and manual drill presses. The 3-piece set typically includes a taper, plug, and bottoming tap, providing full threading capability for both through and blind holes. It is appropriate for machinists, tool and die makers, and maintenance mechanics working with steel, cast iron, and similar ferrous materials.

Key Features

• Thread size: 1-1/8-7 UNC, right-hand direction
• High speed steel construction for durability in ferrous and hard materials
• 4-flute design promotes stable cutting and efficient chip clearance
• Bright finish for general-purpose threading without coating interference
• H4 thread limit supports 2B and 3B class-of-fit tolerances
• 3-piece set covers taper, plug, and bottoming tap stages

Compatibility

Designed for use in standard tapping operations requiring 1-1/8-7 UNC internal threads, compatible with conventional tapping heads, drill presses, and CNC machining centers that accept straight-shank taps of this size range.

Installation Notes

Threading operations with this tap set should be performed by a qualified machinist following established shop practices. Secure the workpiece firmly before tapping and use an appropriate cutting fluid for the material being threaded. Tap in the correct sequence from taper to plug to bottoming tap when threading blind holes. Inspect the tap and hole alignment carefully to avoid tap breakage, which can be difficult to extract in large-diameter threads.