Rockler Bit-Saver Hold Down Clamps 2-Pack

I bought two packages of these clamps in Saskatoon. First time I used one, it would not tighten as the nut is not correctly threaded. Tighten it down and it releases :( Tried the other 3 and I can see at least 2 of them following in the same path. But one of four is not a great return.

I bought two packages of these clamps in Saskatoon. First time I used one, it would not tighten as the nut is not correctly threaded. Tighten it down and it releases :( Tried the other 3 and I can see at least 2 of them following in the same path. But one of four is not a great return.