+1 for these saws, but the blade has limited life if you are cutting reinforcing bar. When cutting large diameters (and I would say 40mm is large), apply a light pressure on the blade but ensure it is cutting all the time. Too heavier a cut fills the blade gullet and causes the teeth to skid, too light and the teeth get too hot as under normal cutting, the heat is dissipated into the chips (swarf).
Do wear all the protective gear as the chips fly off in unpredictable directions ie: down your neck!
Bob Ps: replace the blade once it is blunt