As a homeowner and avid do-it-yourselfer I found these the be well constructed, strong and easy to use. I have only one suggestion. The pilot holes feature a guide to start the hole before using the larger countersink bit. This guide has a small ball-bearing detent to center it but it doesn't quite center it. You have to take a little extra care to make sure it is centered. I marked the clamp and guide to make sure it was centered each time before I used the starter bit. Additionally the countersink bit would not fit entirely into the hole, forcing me to move the clamp to finish the hole. I had to leave one clamp In place while I did this to keep the cabinets aligned and move the clamp and check the alignment to finish the countersink. It's not bad but requires care and planning. Still, I like the clamps.