Good for jobs where jaw opening isn't maxed out

We used the MasterCraft 3" flat spring clamps for a couple of smaller projects. I have to be honest that I wouldn't say they're built for heavy duty jobs as recommended...it could have been a fluke but on one project where we used it to hold our sliding barn door in place, when first trying to get the clamp into place and opening to the max of it's jaw opening (2") when it was clamped, the rubber protection began to come off and we had to re-adjust it a couple times. When used for a small project- just securing a board that needed holes drilled out, they seemed to work fine but the jaw opening was no where near maxed out. I do like that they're carbon steel but I I would recommend using these for jobs where the jaw opening is not maxed and then you should be ok!