I'm going to start changing my own blades on my mower and I need to buy either one. I was wondering if you all think I should get a torque wrench or cordless impact wrench. Will I torque the bolt too much if I use an impact wrench. Also, I will have to use impact sockets, right? I don't have an air compressor either so thats why I was thinking cordless. I just learned they made cordless this morning searching around.