03A043 - Walter 4-40 NC HSS Bottoming Tap for Blind Holes

Precision Threading for Blind Holes

The Walter 03A043 4-40 NC Bottoming Tap is a high-performance cutting tool engineered for professional machining and maintenance applications. Crafted from top-tier High-Speed Steel (HSS), this tap is designed to withstand the rigors of cutting threads into tough materials, including mild steel, stainless steel, and aluminum. Unlike standard carbon steel taps, the HSS construction provides superior heat resistance and edge retention, ensuring a longer service life and consistent thread quality over time.

This specific tool is a "bottoming" tap, characterized by its very short chamfer length of just 1 to 2 threads. This geometry is critical when threading blind holes—holes that do not go all the way through the workpiece. A bottoming tap allows the user to cut full-depth threads virtually to the bottom of the hole, maximizing the grip length for the fastener. It is typically used as the final step in a tapping sequence, following a taper or plug tap which initiates the thread.

Walter Surface Technologies is renowned for precision manufacturing, and this tap features expertly ground threads that reduce friction and torque requirements during operation. The tool is hardened and tempered to strike the perfect balance between hardness for cutting and toughness to resist snapping under load. Whether used for creating new threads in a fabrication project or repairing stripped threads in an MRO setting, the Walter 4-40 NC Bottoming Tap delivers reliability and precision.

Key Technical Specifications

The tap conforms to the 4-40 NC (National Coarse) thread standard, a common size for small machine screws in electronics and precision mechanics. Its ability to handle a diverse range of materials makes it a versatile addition to any machinist's or technician's toolkit. Proper lubrication is recommended during use to further extend tool life and ensure the cleanest possible thread finish.