In view of the fact that these have been made by C & J Hampton, Record, Irwin-Marples and I don't know how many copyists since WWII, and that before Hamptons made them they had been made for probably at least 30 years (they appear to have come about before 1900) I sincerely doubt that any recently discovered flaw exists. But I could be wrong. At the end if the day they clamp onto a joist and push a floorboard tight. You may well find other versions made by Faithfull, Marples (the original Marples firm), Woden, Rededa, Parkinson, Preston, Mathieson, etc which are all of a similar ilk