Originally Posted by VABAM

Which ones? I have a Craftsman 300ftlb 1/2inch impact wrench. They need to be broken in. When I first got it, it wouldn't take off 90ftlb lug nuts. I almost took it back. I had a spare battery from another Craftsman product that was 100% charged and tried it. Even though I had fully charged the battery that came with it the old/used battery made all the difference. The impact wench would finally take the lug nuts off but just barely. After swapping wheels a few time my impact wrench now takes off lug nuts like it is nothing. One thing I noticed is the torque it applies ramps up. It doesn't apply 300ftlbs on the first squeeze of the button but after a few seconds it ramps up the torque. I'm guessing that is a safety feature. Also after cycling the battery that came with a few times, the battery now works 100%. I was annoying that it didn’t work right out of the box but now that is does I’m happy with it.