Jeep2003 has your answer Karen, you take a block of steel and bore a hole the same size as your tubing diameter in the exact center then split the block at the hole so you end up with two identical blocks and then you use em with a press to smash the tube. Sounds easy but it's not, you have to guide the two pieces together with the tube centered while pressing. Ask Jeep, he'll go over it with ya I bet. A dedicated punch press that does it and punches the hole is ideal, I've considered buying dies but they are high rent and I'd maybe ever use em a few times. I have pondered buying a pocket rocket bike and using the components to build myself a Tom Thumb, I would likely use square tubing and build a mini Hound Dog. Gotta get the 7 project minis built or sold first, I'll likely buy even more and never got to it but it's nice to dream. For now I'll watch your build, anxious to see what engine you use. I know a guy who has a bunch of O&R powered drills and other small gas powered tools with O&R engines but shudders when I talk of robbing one off a drill or auger to use for a minibike. There are some high rent Fuji hobby engines out there in 24cc to an 86cc twin, Phil's Hobby Shop sells em.:thumbsup: