"Used to hang a heavy bag with bag spring in my spare room. 10mm long bit to go through the joist and this does a great job. Just need to get a locking nut as it's started to slip. I'll confirm if it takes m10 or 3/8"! (My money's on m10)"
"Good value bolts although a different size to those on invoice but still worked for us. Unsure if the wrong ones were supplied or the details online are incorrect, they were thicker that the description but wasn't a problem for the job we needed them for and meant they would be stronger. Did exactly as they should and expect them to last many years."