Angle grinder usually fits with 4" grinding disc to do grinding or parting off on thin metal, like steel. Just make it clear, yes, no coolant is necessary.
It also can mount with 4" carbide teeth circular cutter, for parting off non-steel metallic material, likes aluminium, wood or etc.. For that applications, care must be taken not to hand-held the angle grinder to do cutting, dangerous!, mounting it rigidly in machine as mentioned previously. And, for aluminium cutting, coolant is necessary.
Thanks