These clamps are poorly made. From the picture it looks like the clamp pliers are made out of something strong and durable but it's safe to say they will break after a week of indoor commercial work. If you're a serious carpenter, take the time to go to your local Rockler or specialty tool store and pick up a real set for less. Waaaaay too expensive for the quality you get. I took them out of the box, showed them to my boss and immediately put them back.