....I think I have sorted it. I had to go for it as I only had so much time before putting an order in for a new belt to arrive within 24 hours, so I used a steel tube. It is a normal right hand thread, but is obviously tight due to the 'Loctite' on thread. If I had sheared the bolt head off, then the machine would have cost me a lot more to fix, which may well have been uneconomical. Thanks for reading...bye