Irwin Hanson 1554 5/8-18 NF Fractional Bottom Tap

The Irwin Hanson 1554 is a high-speed steel bottom tap designed for threading 5/8-inch diameter holes with 18 threads per inch in the NF (National Fine) thread standard. Bottom taps feature a chamfer of only 1-2 threads, allowing them to cut threads very close to the bottom of blind holes where through-holes are not possible.

Key Features:

• 5/8"-18 NF thread specification produces Class 2B internal threads
• Bottom tap design with minimal chamfer for threading close to hole bottoms
• Straight flute design provides efficient chip removal during threading operations
• High-speed steel construction for durability and longevity
• Ideal for routine maintenance, repair work, and rethreading applications
• Designed for hand threading work in a variety of materials

This fractional bottom tap is perfect for creating or repairing fine-pitch internal threads in blind hole applications where standard taps cannot reach. The straight flute geometry ensures reliable chip evacuation while maintaining consistent thread quality. Suitable for use in steel, aluminum, brass, and other common materials found in maintenance and repair work.