2 KudoZ points awarded for this answer. Comment: "I used "bolt" instead of screw, in keeping with the respsonse I got to another question that I posted (also featuring the term "perno"). I also used "coupling" here as I had used it elsewhere in the text, but in hindsight I should have thought of "connection". By now, the client has already received and used my translation. However, as it's merely for use in an e-mail, I really don't think that "coupling" will pose a problem. Thanks for taking the time to respond to my KudoZ question."