https://tinyurl.com/yp8ks7bhAbove is a link to them on Speedway's site. Actually Speedway is one of the companies who sells them branded under their own name (Speedway Motors). Nearly everyone sells them and they've been available for around 40 years. The instructions you get with these are very clear about welding them before using them. Not to say some nitwit didn't just clamp them on and go. It is impossible to predict nitwits.
Several years ago a friend used silver bearing solder to attach these to his axle (that solder as I've mentioned here numerous times will work fine with ferrous metals as long as you understand the principle of cleaning and fluxing). I asked him a couple of years ago and he said they were still doing fine...no problems. Most silver bearing solder has a tensile strength of something over 10,000 PSI (some as much as 18,000) and as you can see there are several square inches of metal to use in this case. You can also braze them in place if you can use an oxy-acetylene rig, but you do have to heat things up more that way. Silver bearing solder melts/flows at a mere 450 degrees. Good luck!
