Hello John, thanks for your feedback, we also sent you 3.8mm wire sample for testing, have you test it? We know different customers use these wires with different method, as this is the first time for us receiving the feedback that 3.4mm wire easily broken, so we emailed you on June 17th and wanted to get some pictures or videos from yourside to find solutions with you together , we didn't receive any answer yet, would you mind contacting us once you get back to office? thanks, have a nice day.