Saddle cut differs for different wall thicknesses. These instructions only work with thin-walled tubing. I was going to use it on 3/16" pipe. The fit is very poor. This should have been in the product description. There are websites that have calculators that will draw a pattern for you. They will make one for a heavier gauge pipe. I have made one for 3/16" walls and it fits much better. I wish this had been explained before I wasted my time and money on this.