Walter 5/16-24 NF HSS Bottoming Tap for Blind Holes

Get Full Threads in Blind Holes

When you are fabricating a part or repairing equipment, running into a blind hole can be a headache if you don't have the right tool. Standard taps often leave unthreaded space at the bottom of the hole due to their long tapered tips. The Walter 03B056 5/16"-24 NF Bottoming Tap is the solution for these tricky situations. Designed specifically for "bottoming out," this tap features a very short lead-in of just 1-2 threads, allowing you to cut clean, precise threads all the way to the bottom of the hole. This ensures your bolts and fasteners have maximum engagement for a secure hold.

Built tough for the shop environment, this tap is crafted from High-Speed Steel (HSS). If you've ever struggled with cheap carbon steel taps that dull instantly or snap off in the work, you will appreciate the difference here. HSS is heat-resistant and maintains its cutting edge far longer, even when you are tapping tougher materials like stainless steel or chromoly. It cuts smoothly through mild steel and aluminum as well, making it a versatile addition to your tap and die set.

The 5/16"-24 National Fine (NF) thread pitch provides a finer adjustment and higher tensile strength compared to coarse threads, which is often preferred in automotive and precision fabrication work. Because bottoming taps have such a short starting taper, they can be harder to start straight by hand compared to a taper tap. It is often best practice to start the threads with a plug tap if possible, and then switch to this Walter bottoming tap to finish the job. However, with care and proper alignment, it cuts aggressively and cleanly.

Don't risk snapping a tap or stripping threads with inferior tools. Walter's precision grinding means less friction and less force required to turn the tap. Pair this with a good tapping fluid, and you'll get professional results every time. Whether you are fixing a stripped thread on an engine block or fabricating a custom bracket, this HSS bottoming tap delivers the reliability welders and fabricators need.