Lol...Its the operator that warps metal....because using the tool with the wrong technique, its heat that warps metal.. (too much pressure on the surface and too coarse grit of paper)....if you dont know what youre doing seek out help. Ive never warped metal because of "cheap" D/A's,.... Ive been doing this for 40 yrs. and if you do get the "cheapie" model, keep it oiled before every use... it'll be fine. :)
