Save you money this does not work! I am revising my review I was a bit too quick to condem.
Like the other two 1 star reviews stated these do not work in 3/4 inch holes. I am very disappointed I have tried sanding the shafts and boring a larger hole in the bottom of the bench top. My top is a little thicker than 4 inches 4 3/32 in thick made of yellow pine. I believe I have tried every possible solution I can find. The holdfast just does not work. I believe they do not flex enough and curve in not right. I later drilled a 3/4 inch hole in another bench top that was about two inches thick and the holdfast worked fine. I apologize to Bill for my hasty negative review.
Rating: 3 stars