10Pcs M16-2 Metric 304 Stainless Steel Hex Nut,304 (A2-70) Stainless Steel Hardware Nuts,Standard Metric Coarse Thread Nuts

They work as they should!

Here are some key points from my experience using them in a home workshop project (securing outdoor metal brackets and some marine-related hardware): Material quality and corrosion resistance: True 304 stainless (equivalent to 18-8/A2 grade), they hold up well in damp or outdoor conditions without any signs of rust after several months of exposure to rain and humidity. Great upgrade over zinc-plated nuts that would typically start spotting quickly. Threading and fit: The coarse 3/8"-16 threads are clean, precise, and consistent across the batch. They threaded smoothly onto matching 304 stainless bolts without cross-threading or galling issues—common with cheaper stainless fasteners if not lubricated. Strength: As A2-70 grade, they provide solid tensile strength (around 700 MPa minimum) for non-structural loads. Held tight under moderate torque without stripping. Finish and appearance: Bright, polished look straight out of the bag—no burrs, machining marks, or defects. The hex flats are sharp and grip wrenches well. One minor note: Like most stainless fasteners, they can gall if over-torqued dry, so a bit of anti-seize or lubricant is recommended for repeated assembly/disassembly.

The nuts are shipped in a fairly sturdy plastic box that was secured with tape to make sure it did not open during shipping. The threads of the nut appear fine as a quality tap goes in cleanly but there is no play once it is fully in the nut. Not all 304 stainless seems to be created equal when it comes to corrosion resistance so I like to do my own test. I use a solution of white vinegar, hydrogen peroxide, and dissolved table salt. The solution will rust mild steel while you watch with quite a bit of rust present within a minute of applying the solution. I applied the solution to a single nut, see picture “Test start”. I then took a picture at two hours showing signs of rust developing. This is fairly typical of 304 stainless steel. 304 strikes a nice balance between corrosion resistance, cost, and strength. I would say this sample had average behavior for 304 that I have tested. These nuts appear to have well-formed threads and reasonable corrosion resistance. They should be durable in all but the most corrosive applications and are a decent value for the price.