What the hell are they made from, I have burned through 2 blades trying to cut one. Theres about 8 years of rust and the nut and bolt have just melted together. Are there any easy ways to remove the clamps or is cutting it the only way?

Mat

 

When i changed my muffler i used an airpowered cut off wheel to cut the band. mine was rusty but it only took about 1 min to cut through it. Then i used a hammer and chisel to break it loose.