Review on 🔩 SPAX Stainless Steel Double Thread Fasteners: Enhancing Screw Performance with Precision by Justin Dorsett

Not a metallurgist or engineer, but the fragility of the bolts makes them virtually useless. Not sure if it's an SS type/class or something. I did a quick test by screwing one of these into stringers I've been working on all day and it blew off the head when screwed in maybe 3/4 the length of the screw. I was working on a set of ladders when they arrived and had drilled and screwed 3 stringers many times that day so I had a pretty good idea of the wood hardness and performance. This has never happened before. I used 2" and 3" GRK Fasteners RT mounting screws but bought them because I liked the head. Small, narrow head of #8" x 2" GRK fasteners. The RT overhead screws (and the 3" version) might go through. simpler, so I looked for an alternative. In comparison, GRK screws would simply tear this wood apart without pre-drilling. I usually pre-drill everything just to prevent wood splitting etc. But I didn't do that when I took the test. You'll probably get much better results if you pre-drill them, but I wanted to test their strength. Perhaps they would be ideal if you pre-drilled everything and would have to use SS due to the environment they would be in. I love the concept and design.