I've read the reviews written by others here and cannot imagine why none of you even tried to contact customer service for these problems. I've owned four of them for about 7 years now and never had a problem. However, I too broke one of my clamps with the pot-metal head and was very dissappointed in them for awhile.
  I bought a new one to replace it and immediately noticed that the head mechanism was made of ductile iron and I knew the company had recognized the problem and fixed it.
  I stared at that broken clamp for about a month. (I rarely throw something away that I think I might use). Anyway, I decided to contact customer service via email.  Whoa, what a surprise I got!  I recieved a personal reply for a customer service representative saying they were shipping me parts to repair my clamps within an hour. That was last week. I recieved the parts yesterday, about a week later, have installed them.
  I'm very happy that I won't likely break another clamp head.  I am also very impressed with the speed and willingness of the company to remedy my problem.  They also have a little spacer available to prevent them from locking closed as mentioned above, but I didn't get those.
  Go to Adjustable Clamp Company's website and let them know if you have a problem with their clamps. A Made-In-America product with good old-fashioned American service and support. I'll buy Jorgensen clamps whenever possible.
I've read the reviews written by others here and cannot imagine why none of you even tried to contact customer service for these problems. I've owned four of them for about 7 years now and never had a problem. However, I too broke one of my clamps with the pot-metal head and was very dissappointed in them for awhile. I bought a new one to replace it and immediately noticed that the head mechanism was made of ductile iron and I knew the company had recognized the problem and fixed it. I stared at that broken clamp for about a month. (I rarely throw something away that I think I might use). Anyway, I decided to contact customer service via email. Whoa, what a surprise I got! I recieved a personal reply for a customer service representative saying they were shipping me parts to repair my clamps within an hour. That was last week. I recieved the parts yesterday, about a week later, have installed them. I'm very happy that I won't likely break another clamp head. I am also very impressed with the speed and willingness of the company to remedy my problem. They also have a little spacer available to prevent them from locking closed as mentioned above, but I didn't get those. Go to Adjustable Clamp Company's website and let them know if you have a problem with their clamps. A Made-In-America product with good old-fashioned American service and support. I'll buy Jorgensen clamps whenever possible.