Hi Terry,
Similar to Ians comment above, I would use one of these discs in a grinder, these leave a good finish, and as they are only 0.6mm thick (from memory) are not too aggressive. Also, when I have needed to control the cut, I have clamped a piece of scrap onto the part being cut, with the edge on the cutting line – this provides a cutting guide, and I've had good results like this.
LINK
James