Hertel K008629AS Straight Flute Tap 1-8 Unc Hss

Product Description

The HERTEL K008629AS is a straight flute tap designed for cutting 1-8 UNC internal threads in a right-hand direction. Built from high speed steel with a bright/uncoated finish, this tap features four flutes and a taper chamfer for guided thread entry. It carries a Class 3B fit rating and an H4 thread limit, making it appropriate for precision threading applications where close tolerance control is required. The overall length measures 5.125 inches. This tool is used by machinists and maintenance trades in production and repair environments where reliable thread forming in steel, cast iron, and similar materials is needed.

This tap is suited for through-hole and blind-hole threading operations in general-purpose machining, toolroom work, and MRO maintenance environments. The taper chamfer distributes cutting load over several leading threads, reducing the torque required to start the cut and lowering the risk of tap breakage at entry. It is appropriate for manual tapping as well as low-speed machine tapping on drill presses and milling machines where operator feel and controlled feed are maintained. Coolant-through capability is not included, so conventional flood or brush-applied cutting fluid should be used as needed.

Key Features

• 1-8 UNC thread form with Class 3B fit for close-tolerance internal threads
• H4 thread limit provides controlled oversize allowance for plating or tight tolerance work
• Four straight flutes for efficient chip clearance in through-hole applications
• Taper chamfer distributes entry load across multiple threads to reduce breakage risk
• High speed steel construction offers good wear resistance across a range of workpiece materials
• Bright/uncoated finish suitable for use with standard cutting fluids

Compatibility

Designed as a standard straight flute tap for 1-8 UNC threading operations on compatible manual and machine tapping setups that accept standard tap shank dimensions.

Installation Notes

This tap should be installed by a qualified machinist or toolroom professional. Secure the workpiece fully before tapping and ensure the tap is started square to the hole to prevent thread misalignment or breakage. Apply appropriate cutting fluid throughout the operation and back off periodically to break chips when working in deeper holes. Follow shop safety practices and applicable OSHA standards when operating tapping equipment.