Walter 5/16-18 NC HSS Bottoming Tap for Blind Holes

Professional Grade Threading Solutions

When you are in the middle of a fabrication project or a critical repair, the last thing you need is a broken tap stuck in your workpiece. The Walter 5/16"-18 NC Bottoming Tap (SKU: 03B053) is built to give welders, mechanics, and fabricators the confidence they need when creating or restoring threads. Made from superior High-Speed Steel (HSS), this tap offers significantly better performance and longevity compared to standard hardware store carbon steel taps. It is specifically designed to cut clean, accurate threads in a variety of metals, including mild steel, aluminum, and even tougher stainless steel alloys often found in welding shops.

This specific model is a "bottoming" tap, which is a critical distinction for anyone working with blind holes. A blind hole is one that doesn't pass completely through the material. Standard taps have a long tapered tip that hits the bottom of the hole before full threads are cut, leaving the last portion of the hole useless. The Walter bottoming tap has almost no taper—only 1 to 2 threads—allowing you to thread virtually all the way to the bottom. This maximizes the thread engagement length, which is vital for ensuring bolts hold securely in shallow holes or heavy-duty applications.

Walter Surface Technologies is known for producing industrial-grade tools that stand up to daily abuse, and this tap is no exception. The threads are precision ground to ensure they cut smoothly and reduce the effort required to turn the tap. This reduces operator fatigue and minimizes the risk of the tap wandering or cross-threading. Whether you are tapping a new fixture plate, repairing a stripped engine block mount, or fabricating custom brackets, this HSS bottoming tap ensures the job is done right the first time.

Shop Essentials for Fabricators

Every well-equipped welding and fabrication shop needs a reliable set of taps. The 5/16"-18 coarse thread is one of the most common sizes used in North America, making this a high-turnover tool that you should always have on hand. To get the best results, we recommend using a proper tapping fluid or paste, especially when working with stainless steel. This helps clear chips and keeps the cutting edges sharp. Invest in Walter quality to avoid the headaches of broken tools and ruined workpieces.